The following sentence has a blank indicating that something has been left out Beneath the sentence are four words or phrases Choose the word or phrase that, when inserted in the sentence, best fits the meaning of the sentence as a whole.

Poison frogs become poisonous by isolating chemicals from their food and storing them in their skin. One such compound, epibatidine, is a stronger painkiller than morphine, but has not been tested in humans because even low doses are deadly to rodents. But for the frogs themselves, this powerful neurotoxin is totally impotent. According to a study published in Science, several groups of epibatidine-bearing frogs have independently evolved amino acid changes in the toxin's target, the nicotinic acetylcholine receptor. These modifications allow the amphibians to escape self-toxicity.

(1) When selecting her ingredients, a chef has a seemingly small—but nonetheless consequential—choice: she can patronize a conventional grocery store, or she can turn to a nearby farm. (2) While a store may provide benefits such as a broad range of options, a local farm can offer major advantages of its own. (3) When chefs and other consumers choose local products rather than goods that have been transported across long distances to chain stores, they can enjoy better prices while supporting the local economy. (4) Shoppers buying locally can often reap the benefits of competitive prices on goods due to reduced transport costs. (5) For example, one researcher found that the ingredients of a common Swedish breakfast—consisting of items like bread, coffee, and orange juice—were probably shipped a distance roughly equivalent to Earth’s circumference, and shipping can be costly. (6) On the other hand, buying ingredients from local farms may reduce transportation costs significantly, thereby increasing savings for the consumer. (7) Research also suggests that small local farms collectively can produce a large quantity of food; a big supply can, in turn, translate into lower prices. (8) Small farms gain these yields in part through efficient land use. (9) One study found that in Brazil, nearly five million small farms—which occupy only about 30 percent of the country's total agricultural land—are able to produce most of the beans the country needs. (10) The law of supply and demand suggests that if local farmers can produce more food than large farms, consumers may pay less. (11) Lower prices are not the only potential advantage of buying locally. (12) When consumers shop nearby, they are helping to ensure that local farms and businesses thrive. (13) The Brazilian bean farmers, for example, can continue to build strong local economies and do not have to migrate to commercial farms to find work. (14) What will our chef choose? (15) Deciding where to shop can be enigmatic, as both the store and the farm have their attractions. (16) The local option often makes the most sense, however. (17) It is good for the chef’s wallet, the neighborhood farmer’s bottom line, and, in the end, the community’s economic vigor.

(1) When selecting her ingredients, a chef has a seemingly small—but nonetheless consequential—choice: she can patronize a conventional grocery store, or she can turn to a nearby farm. (2) While a store may provide benefits such as a broad range of options, a local farm can offer major advantages of its own. (3) When chefs and other consumers choose local products rather than goods that have been transported across long distances to chain stores, they can enjoy better prices while supporting the local economy. (4) Shoppers buying locally can often reap the benefits of competitive prices on goods due to reduced transport costs. (5) For example, one researcher found that the ingredients of a common Swedish breakfast—consisting of items like bread, coffee, and orange juice—were probably shipped a distance roughly equivalent to Earth’s circumference, and shipping can be costly. (6) On the other hand, buying ingredients from local farms may reduce transportation costs significantly, thereby increasing savings for the consumer. (7) Research also suggests that small local farms collectively can produce a large quantity of food; a big supply can, in turn, translate into lower prices. (8) Small farms gain these yields in part through efficient land use. (9) One study found that in Brazil, nearly five million small farms—which occupy only about 30 percent of the country's total agricultural land—are able to produce most of the beans the country needs. (10) The law of supply and demand suggests that if local farmers can produce more food than large farms, consumers may pay less. (11) Lower prices are not the only potential advantage of buying locally. (12) When consumers shop nearby, they are helping to ensure that local farms and businesses thrive. (13) The Brazilian bean farmers, for example, can continue to build strong local economies and do not have to migrate to commercial farms to find work. (14) What will our chef choose? (15) Deciding where to shop can be enigmatic, as both the store and the farm have their attractions. (16) The local option often makes the most sense, however. (17) It is good for the chef’s wallet, the neighborhood farmer’s bottom line, and, in the end, the community’s economic vigor.