Aclient has recently been prescribed a drug that treats hypertension by blocking the sympathetic receptors in the sympathetic nervous system. this action is characteristic of which?

An adrenergic antagonist.

Explanation:

Hypertension is also known as high blood pressure that might occurs due to the long term pressure on the walls of the artery. This might cause the health related problems like heart attack.

An adrenergic antagonist is the drug that might inhibits the different function of the adrenergic receptor. These receptors are located in the walls of the arteries, hearts. The adrenergic drug  are used for the treatment of the hypertension.

Thus, the answer is an adrenergic antagonist.

c would be the answer