What effect do stimulants have on the body?

Stimulants are a class of drugs that primarily enhance activity in the central nervous system. They increase the levels of certain neurotransmitters, such as dopamine and norepinephrine, which leads to heightened alertness, increased energy, and greater focus. This is particularly observed in substances such as caffeine, amphetamines, and cocaine.

The effects of stimulants include improved cognitive processes and increased physical performance, making people feel more awake and engaged. This characteristic makes option C the correct choice, as it accurately captures the primary action of stimulants on the body.

The other options reflect effects that are not aligned with the pharmacological activities of stimulants. For example, stimulants do not induce relaxation; instead, they tend to produce feelings of excitement or anxiety. Additionally, they do not inhibit seizures; in fact, certain stimulants can potentially provoke seizures in susceptible individuals. Lastly, stimulants generally increase heart rate rather than decrease it, which is a key aspect of their stimulating effects on the body.