The clinical signs consisting of sweating, urination, salivation, and miosis are most probably associated with which agent

The answer would be nerve

The nerve is responsible for regulating many mechanisms. All of the symptoms that described above is related to the autonomous nervous system, specifically parasympathetic nervous system. It has a role in resting and digesting food, in contrast to sympathetic that regulates "fight or flight" mechanism.

Drugs that elicit these symptoms would be acetylcholine or other cholinergic drugs.