## **Core Concept**
The question tests the knowledge of antihypertensive agents and their side effects, specifically focusing on their impact on sexual function, particularly libido. Different classes of antihypertensive drugs have varying side effect profiles, including effects on sexual function.

## **Why the Correct Answer is Right**
The correct answer, , is known to decrease libido as a side effect. This class of drugs, specifically the non-selective beta-blockers like propranolol, can affect sexual function. Beta-blockers can decrease libido and cause erectile dysfunction by affecting the beta-2 receptors in the vascular smooth muscle and possibly through central effects.

## **Why Each Wrong Option is Incorrect**
- **Option A:** - This class of drugs is not commonly associated with decreased libido as a primary side effect. In fact, ACE inhibitors are often considered to have a more favorable side effect profile regarding sexual function.
- **Option B:** - While certain antihypertensive agents can cause sexual dysfunction, this option does not specifically point to a well-known class associated with decreased libido.
- **Option D:** - This option is not directly linked to a significant decrease in libido compared to the correct answer.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that beta-blockers, especially non-selective ones, are associated with sexual side effects, including decreased libido. This is an important consideration in the management of hypertension, especially in younger patients or those with concerns about sexual function.

## **Correct Answer:** . Propranolol