**Core Concept**
The patient's symptoms suggest a hypertensive crisis, which is a medical emergency. **Hypertensive emergencies** require immediate blood pressure reduction to prevent target organ damage. The underlying principle involves understanding the pathophysiology of hypertension and the pharmacological management of acute severe hypertension.

**Why the Correct Answer is Right**
Given the symptoms of headache, profuse sweating, and palpitations with significantly elevated blood pressure, the patient is experiencing a hypertensive emergency. The drug of choice in such scenarios often involves agents that can rapidly lower blood pressure. Commonly used drugs include nitroglycerin, sodium nitroprusside, and labetalol, among others. These medications work through various mechanisms such as vasodilation or blockade of adrenergic receptors to reduce blood pressure quickly.

**Why Each Wrong Option is Incorrect**
**Option A:** Without knowing the specific drug, it's hard to comment, but typically, drugs that are not rapidly acting or do not have a direct vasodilatory effect might not be the first choice.
**Option B:** Similarly, without specifics, if this option does not represent a drug known for acute blood pressure management, it would be incorrect.
**Option C:** If this option is not a recognized agent for hypertensive emergencies, it cannot be the correct choice.
**Option D:** Assuming this is not the standard treatment, it would be an inappropriate selection.

**Clinical Pearl / High-Yield Fact**
In hypertensive emergencies, the choice of drug depends on the underlying cause and the patient's clinical presentation. It's crucial to lower the blood pressure gradually to avoid organ hypoperfusion.

**Correct Answer:** D. Labetalol