Final answer:
Cocaine is the stimulant drug in the given options
Step-by-step explanation:
The correct answer is b. cocaine.
Cocaine is a stimulant drug that affects the central nervous system. It increases levels of dopamine, a neurotransmitter associated with pleasure and reward, leading to feelings of euphoria and increased energy.
Unlike alcohol, diazepam, and mathaqualone, which are depressants that slow down the activity of the brain and nervous system, cocaine has stimulating effects.
Learn more about Stimulant drugs