Final answer:
A drug that alters mood, perception, or thought is called a psychoactive drug. These drugs influence the central nervous system by affecting neurotransmitters in the brain. The correct answer is a. psychoactive drug.
Step-by-step explanation:
Any drug that alters mood, perception, or thought is called a psychoactive drug. These are substances that change the function of the brain and result in alterations of mood, thinking, perception, and/or behavior. Psychoactive drugs can encompass a wide range of substances, including prescription medications such as opioid painkillers, legal substances such as alcohol and nicotine, and illegal drugs such as LSD and heroin.
Psychoactive drugs are categorized into different classes like stimulants, depressants, hallucinogens, etc., based on their pharmacological effects. They may have one or multiple effects, which can sometimes lead to confusion as to how they are classified. It is important to understand that the term psychoactive drug encompasses both legal and illicit substances, and their legality can vary depending on jurisdiction and context. So, the correct answer is a. psychoactive drug.