Final answer:
Graham took a psychoactive drug classified as a stimulant, which from the provided options is Cocaine. It stimulates the brain, increasing alertness and wakefulness, unlike the other options like Marijuana, Heroin, and LSD which have different effects on the central nervous system.
Step-by-step explanation:
Psychoactive drugs are substances that influence the central nervous system and alter functions of the brain which can lead to changes in mood, perception, thinking, and behavior.
Among them, some are used recreationally to induce a euphoric state known as a "high." Within this category of substances, drugs are further classified based on their effects. Stimulant drugs, specifically, are designed to increase alertness and wakefulness by stimulating the brain.
The question asks which drug Graham took, classified as a stimulant, from the provided options. Therefore, the correct answer to the question is A.
Cocaine, which is a psychoactive drug known for its stimulating effects on the brain, leading to increased levels of alertness and energy.
Unlike cocaine, Marijuana is mainly categorized as a depressant with some hallucinogenic properties, Heroin is an opioid and depressant, and LSD is primarily a hallucinogen which significantly alters perception and mood but is not a stimulant.