**Core Concept**
The patient's presentation with chest pain and ST segment depression on an ECG in leads V1-V4 suggests myocardial ischemia, specifically a non-ST elevation myocardial infarction (NSTEMI). This condition is characterized by reduced blood flow to the heart muscle, leading to tissue damage.

**Why the Correct Answer is Right**
The primary goal in managing NSTEMI is to restore blood flow to the affected area of the heart. Administering beta-blockers, such as **metoprolol** (Option C), is a common practice to reduce myocardial oxygen demand by decreasing heart rate and blood pressure. However, administering **nitroglycerin** (Option A) is not recommended in this scenario because it can worsen myocardial ischemia by reducing coronary perfusion pressure.

**Why Each Wrong Option is Incorrect**
* **Option A:** Nitroglycerin can decrease coronary perfusion pressure, which may worsen ischemia in NSTEMI patients.
* **Option B:** This option is missing, but typically would be a distractor. For example, if the distractor were **furosemide**, it would be incorrect because furosemide is a diuretic and not a primary treatment for NSTEMI.
* **Option D:** This option is also missing, but if it were **aspirin**, it would be incorrect because aspirin is actually recommended in the management of NSTEMI due to its antiplatelet effects.

**Clinical Pearl / High-Yield Fact**
When managing NSTEMI, it's essential to remember that beta-blockers reduce myocardial oxygen demand, while nitrates can worsen ischemia by decreasing coronary perfusion pressure. This distinction is crucial in selecting the most appropriate treatment.

**Correct Answer:** A. Nitroglycerin should not be given.