**Core Concept**
Pheochromocytoma is a rare neuroendocrine tumor that arises from the adrenal medulla, leading to the excessive secretion of catecholamines, including adrenaline and noradrenaline. These hormones cause a range of symptoms, primarily related to the cardiovascular and nervous systems.

**Why the Correct Answer is Right**
The symptoms of pheochromocytoma are typically associated with the 'fight or flight' response, mediated by the sympathetic nervous system. **Episodic hypertension**, **paroxysms of palpitation**, and **sweating** are classic presentations, as catecholamines cause vasoconstriction, tachycardia, and increased vascular resistance. **Flushing of the skin** can also occur due to vasodilation and increased blood flow to the skin. In contrast, **episodic diarrhea** is not a typical manifestation of pheochromocytoma, as catecholamines primarily affect the cardiovascular and nervous systems rather than the gastrointestinal tract.

**Why Each Wrong Option is Incorrect**
**Option B:** Flushing of the skin is a possible symptom of pheochromocytoma due to vasodilation and increased blood flow.
**Option C:** Episodes of hypertension are a hallmark of pheochromocytoma, resulting from excessive catecholamine secretion.
**Option D:** Paroxysms of palpitation, sweating, and other symptoms are characteristic of pheochromocytoma, reflecting the 'fight or flight' response.

**Clinical Pearl / High-Yield Fact**
Pheochromocytomas are often associated with other endocrine disorders, such as multiple endocrine neoplasia (MEN) syndromes, and can be caused by mutations in genes like VHL, RET, or SDHB. Remember the classic symptoms and the importance of considering pheochromocytoma in patients with unexplained episodic hypertension and 'fight or flight' symptoms.

✓ Correct Answer: A. Episodic diarrhea