Final answer:
Alcohol is a depressant that acts as a potent sedative, particularly when paired with a lack of sleep, affecting the central nervous system. The correct answer is option: a. sedative.
Step-by-step explanation:
Alcohol, known scientifically as ethanol, belongs to a class of psychoactive drugs referred to as depressants. When paired with lack of sleep, alcohol acts as a sedative, exacerbating its depressant effects on the central nervous system.
Symptoms of alcohol intoxication include sedation, poor coordination, lowered alertness, and even respiratory depression in extreme cases.
Importantly, depressants like alcohol can lead to physical and psychological dependence with repeated use. Therefore, the correct answer to the question is that alcohol, especially when combined with a lack of sleep, is a potent sedative.