Which scenario demonstrates the use of stratified sampling?

While this scenario involves sampling from distinct regions, it does not illustrate stratified sampling because the researcher is not taking samples from each of the regions; instead, they are selecting a few regions entirely. Stratified sampling requires obtaining samples from all identified subgroups, not just a random selection of them.

This represents systematic sampling rather than stratified sampling. In systematic sampling, a fixed interval is used to select participants from the population, rather than dividing the population into strata and sampling from each one, which is essential for stratified sampling.

This scenario describes simple random sampling, where every individual has an equal opportunity to be chosen, without any consideration for different strata within the population. Stratified sampling, on the other hand, necessitates dividing the population into subgroups and sampling from each one.