Which definition matches a stimulant?

• A. A drug that slows the central nervous system
• B. A drug that increases the action of the central nervous system, the heart, and other organs
• C. A device that measures blood pressure
• D. A drug that causes sedation

Answer: (B)

A stimulant is a substance that increases activity in the body's nervous system and other organs. It boosts brain activity, raising alertness, energy, and focus, and it also heightens physiological arousal like heart rate and blood pressure as part of the body's sympathetic response. That’s why the best description is the one that says the drug increases the action of the central nervous system, the heart, and other organs. The other ideas describe slowing the brain (depressants) or refer to something that isn’t a drug at all (a device to measure blood pressure), so they don’t fit the concept of a stimulant. Common examples include caffeine, nicotine, and certain prescription or illegal stimulants; these can be safe in some contexts but may cause problems like insomnia, anxiety, or heart issues if misused.