Which of the following symptoms is associated with both amphetamines and cocaine?

The correct choice is hallucination. Both amphetamines and cocaine are stimulants that can lead to a range of psychological effects, including altered perceptions and hallucinations. These substances influence neurotransmitter levels, particularly dopamine, which can result in intense euphoria, increased energy, and, in some cases, psychotic symptoms such as visual or auditory hallucinations.

Hallucinations occur because these substances significantly affect the brain's reward pathways and can lead to an overstimulation of the central nervous system. Prolonged use or high doses can increase the likelihood of experiencing these symptoms.

Other symptoms associated with amphetamines and cocaine include increased heart rate, agitation, and increased energy levels, which may differ from the symptoms listed in the other answer choices.