________ is a set of physiological and behavioral symptoms that result when people who have been using substances heavily for prolonged periods of time stop or greatly reduce their use.

A) Substance withdrawal
B) Substance intoxication
C) Substance abuse
D) Substance dependence

Substance withdrawal refers to the symptoms experienced when a person stops or reduces their use of a substance they have been heavily using for a prolonged period. These symptoms can vary depending on the substance used and include physical discomfort, nausea, anxiety, depression, and cravings for the substance. Withdrawal symptoms can make it difficult for people to quit using a substance, as they often feel compelled to use again to alleviate the symptoms.