Which neurotransmitter is associated with arousal?

The correct response to the question regarding the neurotransmitter associated with arousal is norepinephrine. This neurotransmitter plays a critical role in the body's response to stress and helps regulate alertness and attentiveness. When norepinephrine is released in the brain, it contributes significantly to processes involved in arousal, such as increasing heart rate and activating the fight-or-flight response.

While the other neurotransmitters listed also have important functions in the body and brain, they are not primarily linked to the concept of arousal in the same direct way. Dopamine is mainly associated with pleasure, reward, and motivation, whereas epinephrine, although it can influence arousal in terms of preparing the body for action during stressful situations, is more of a hormone than a neurotransmitter in the central nervous system context. Acetylcholine plays a role in attention and neuronal signaling but is not considered the primary neurotransmitter for arousal.

Therefore, norepinephrine's specific role in enhancing alertness and readiness makes it the most appropriate choice for this question.