Milton has been having considerable trouble with his short-term memory. his family has noticed a number of mistakes milton has been making, such as leaving doors unlocked, getting lost in the neighborhood, and forgetting family members' names. it appears that his neurons are deteriorating.

B. ACh                    

Explanation:

ACh or acetylcholine is the neurotransmitter, which is found in the sympathetic and parasympathetic neurons in the nervous system. Acetylcholine is kept or stored in vesicles at the ends of cholinergic neurons. It serves both as excitatory as well as inhibitory functions, which indicates that ACh can slow down or speed up nerve signals. It plays an important role in memory, arousal, neuroplasticity and, learning.