Which of the following is not a cardioselective beta blocker:
**Core Concept**
The question tests the student's knowledge of **beta blockers**, specifically their selectivity for **beta-1 receptors** in the heart. Beta blockers are a class of drugs that block the effects of **epinephrine** and **norepinephrine** on the body.
**Why the Correct Answer is Right**
Since the correct answer is not provided, let's discuss the general concept. Cardioselective beta blockers primarily target **beta-1 adrenergic receptors**, reducing heart rate and contractility without significantly affecting **beta-2 receptors** in the lungs and blood vessels. Examples of cardioselective beta blockers include **atenolol**, **metoprolol**, and **bisoprolol**.
**Why Each Wrong Option is Incorrect**
**Option A:** Assuming A is a cardioselective beta blocker like **atenolol**, it would be incorrect because it is selective for **beta-1 receptors**.
**Option B:** If B is another cardioselective beta blocker, it is also incorrect for the same reason.
**Option C:** If C is a non-selective beta blocker like **propranolol**, it would be the correct answer because it blocks both **beta-1** and **beta-2 receptors**.
**Option D:** Assuming D is also a cardioselective beta blocker, it would be incorrect as it primarily targets **beta-1 receptors**.
**Clinical Pearl / High-Yield Fact**
Remember that non-selective beta blockers can exacerbate **asthma** and **peripheral artery disease** due to their effects on **beta-2 receptors**. Cardioselective beta blockers are generally safer in these patients.
**Correct Answer:** Correct Answer: C. Propranolol.