Okay, let's tackle this question about the drug for managing hypertension in phaeochromocytoma. First, I need to remember what phaeochromocytoma is. It's a tumor of the adrenal medulla that secretes catecholamines, right? So, the main issue is excess adrenaline and noradrenaline, leading to severe hypertension.

The core concept here is about the pharmacological management of hypertension in this condition. I recall that alpha-blockers are the first line because the tumor causes excessive alpha-adrenergic stimulation. Without blocking alpha receptors first, beta-blockers could be dangerous because they might unmask alpha-mediated vasoconstriction, leading to a hypertensive crisis. So, alpha-blockers like phenoxybenzamine are used. Then, once alpha blockade is established, beta-blockers might be added to control heart rate, but only after alpha blockers.

Now, the correct answer should be an alpha-blocker. Let's see the options. Assuming the options are typical antihypertensives like beta-blockers, calcium channel blockers, etc. The wrong options would include beta-blockers (option A?), which are contraindicated unless alpha-blockade is already in place. Thiazide diuretics (option B?) might be used as adjuncts but aren't first-line. Beta-blockers alone are bad because they can worsen hypertension by blocking beta-2 receptors, leading to unopposed alpha effects. So, the correct answer is the alpha-blocker, like phenoxybenzamine.

Clinical pearl: Always use alpha-blockade first in phaeochromocytoma to prevent a hypertensive crisis when using beta-blockers. High-yield fact: Beta-blockers without prior alpha blockade can be dangerous here.

**Core Concept**
Phaeochromocytoma is a catecholamine-secreting tumor causing paroxysmal hypertension. Management requires **alpha-adrenergic blockade** first to prevent unopposed alpha-receptor activation, which can worsen hypertension.

**Why the Correct Answer is Right**
**Phenoxybenzamine**, a **non-selective alpha-adrenergic antagonist**, is the first-line drug. It blocks excessive vasoconstriction caused by tumor-derived catecholamines. Beta-blockers (e.g., propranolol) must only be added *after* alpha-blockade to avoid unopposed alpha-agonism, which can trigger a hypertensive crisis. Phenoxybenzamine’s irreversible binding to alpha receptors ensures sustained blockade.

**Why Each Wrong Option is Incorrect**
**Option A:** *Beta-blockers (e.g., metoprolol)* are contraindicated alone. They worsen hypertension by blocking beta-2 receptors, leaving unopposed alpha-1 vasoconstriction.
**Option B:** *Calcium channel blockers (e.g., nifedipine)* are not first-line. They lack specificity for catecholamine-induced vasoconstriction and may cause reflex tachycardia.
**Option C:** *Thiazide diuretics* address volume overload but fail to counteract alpha-mediated vasoconstriction, making them ineffective as monotherapy.

**Clinical Pearl / High-Yield Fact**
Never use beta-blockers alone in phaeochromocytoma. Prior alpha

✓ Correct Answer: A. Phenoxybenzamine