**Core Concept**
The question is testing the student's knowledge of a specific pharmacological agent, its mechanism of action, and its clinical application. The correct answer is a medication used to manage a particular medical condition, which requires a thorough understanding of pharmacodynamics and pharmacokinetics.

**Why the Correct Answer is Right**
The correct answer is a beta-blocker that is primarily used to treat hypertension and heart failure. It works by selectively blocking beta-1 adrenergic receptors in the heart, which leads to a decrease in heart rate and contractility. This results in a reduction in cardiac output and a decrease in blood pressure. The medication also has a mild vasodilatory effect due to its ability to inhibit the release of norepinephrine from the sympathetic nervous system.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it is a medication used to treat angina, not hypertension or heart failure. It works by increasing blood flow to the heart muscle through vasodilation.
**Option B:** This option is incorrect because it is an alpha-blocker, which is used to treat benign prostatic hyperplasia and hypertension, but not heart failure.
**Option C:** This option is incorrect because it is a calcium channel blocker, which is used to treat hypertension, angina, and heart failure, but it works through a different mechanism than the correct answer.

**Clinical Pearl / High-Yield Fact**
When choosing a beta-blocker for the treatment of hypertension or heart failure, it is essential to consider the patient's specific clinical profile, including their heart rate, ejection fraction, and comorbidities. The correct choice of beta-blocker can significantly impact patient outcomes and reduce the risk of adverse effects.

**Correct Answer:** B. Metoprolol