Which of the following terms best describes when a person's tissue cells have adjusted to the presence of a drug?

Habituation refers to a decrease in response to a stimulus after repeated exposure. While it describes a psychological adjustment to stimuli, it does not specifically relate to the physiological changes that occur in tissue cells as a result of prolonged drug use. Therefore, it is not an appropriate term for the adjustment of cells to a drug's presence.

Physical addiction denotes a state where the body relies on a drug to function normally and experiences withdrawal symptoms without it. While related to drug use, it emphasizes dependence rather than the specific cellular adaptations that define tolerance. Thus, it does not accurately describe the adjustment of tissue cells to a drug.

Dependence involves a state where an individual requires a drug to avoid withdrawal symptoms. While it is closely related to tolerance, it focuses more on the psychological and physical reliance on the substance rather than the specific cellular adjustments that occur with continued drug exposure.