Signs and symptoms of exposure to a nerve agent include:a. dry mouth, dilated pupils, and headache. b. salivation, pinpoint pupils, and diarrhea. c. tachycardia, flushed skin, and unequal pupils. d. hypertension and severe pulmonary edema.

b. salivation, pinpoint pupils, and diarrhea

Explanation:

Nerve agents disrupt the normal functioning of nervous system. They inhibit the breakdown of neurotransmitter acetylcholine due to which nerve impulses are generated continuously. As a result the muscles are not able to relax which can prove fatal for the victim.

Due to non stop activity of muscle fibers unnecessary salivation occurs. Involuntary urination and defecation is also observed as in the case of diarrhea. The pupils remain constricted and give the appearance of pin point pupils. Examples of nerve agents are Sarin and Tabun.