Identify a stimulant example.

• A. Morphine
• B. Marijuana
• C. Alcohol
• D. Cocaine

Answer: (D)

Stimulants speed up the central nervous system, increasing alertness, energy, and heart rate. Cocaine fits this category because it blocks the reuptake of dopamine, norepinephrine, and serotonin, causing a surge of these neurotransmitters. That surge boosts arousal and energy and elevates cardiovascular activity like heart rate and blood pressure. The other substances don’t act as stimulants in this sense: morphine is an opioid that depresses CNS activity and relieves pain; marijuana can alter mood and perception but isn’t a classic stimulant and can have depressant effects at typical use; alcohol is a central nervous system depressant that reduces alertness and coordination. So cocaine is the stimulant example.