Which substance is listed as a stimulant in the material?

Which substance is listed as a stimulant in the material?

• A. Cocaine
• B. Water
• C. Caffeine
• D. Vitamin C

Answer: (A)

Stimulants are substances that speed up the body's nervous system, increasing alertness, energy, and heart rate. Cocaine is classified as a stimulant because it blocks the dopamine transporter, causing more dopamine to stay in the brain's synapses. That buildup heightens arousal and activity in brain circuits related to mood and energy, which is why it’s listed as a stimulant in the material. Water doesn’t affect brain activity in this way—it's simply needed for hydration. Vitamin C is a nutrient with antioxidant roles and isn’t a stimulant. Caffeine is another example of a stimulant, but the material in question specifically lists cocaine as the stimulant, making it the correct choice.

Stimulants are substances that speed up the body's nervous system, increasing alertness, energy, and heart rate. Cocaine is classified as a stimulant because it blocks the dopamine transporter, causing more dopamine to stay in the brain's synapses. That buildup heightens arousal and activity in brain circuits related to mood and energy, which is why it’s listed as a stimulant in the material. Water doesn’t affect brain activity in this way—it's simply needed for hydration. Vitamin C is a nutrient with antioxidant roles and isn’t a stimulant. Caffeine is another example of a stimulant, but the material in question specifically lists cocaine as the stimulant, making it the correct choice.