**Core Concept**
Scurvy is a disease caused by a deficiency of vitamin C (ascorbic acid), leading to impaired collagen synthesis and connective tissue damage. Perifollicular and petechial hemorrhages are key clinical manifestations of scurvy, resulting from the degradation of collagen and elastin in blood vessel walls.

**Why the Correct Answer is Right**
The correct answer is scurvy because it directly relates to the pathophysiology of vitamin C deficiency. Vitamin C is essential for the hydroxylation of proline and lysine residues in collagen, a process necessary for the stabilization of collagen triple helices. Without sufficient vitamin C, collagen synthesis is impaired, leading to the degradation of existing collagen and elastin in blood vessel walls. This degradation causes blood vessels to become fragile and prone to rupture, resulting in perifollicular and petechial hemorrhages.

**Why Each Wrong Option is Incorrect**
**Option A:** Acrodermatitis enteropathica is a rare genetic disorder characterized by impaired zinc absorption, not vitamin C deficiency. It presents with skin lesions, alopecia, and diarrhea, but not perifollicular and petechial hemorrhages.

**Option B:** Pellagra is a disease caused by niacin deficiency, leading to dermatitis, diarrhea, dementia, and potentially death. While it does cause skin lesions, they are not typically perifollicular or petechial in nature.

**Option D:** Phrynoderma is a condition characterized by dry, scaly skin and follicular hyperkeratosis, often seen in patients with malnutrition or zinc deficiency. It does not typically present with perifollicular and petechial hemorrhages.

**Clinical Pearl / High-Yield Fact**
Remember that scurvy can be caused by a diet lacking fresh fruits and vegetables, as well as by conditions that impair vitamin C absorption, such as celiac disease or Crohn's disease. Be aware of the classic triad of scurvy: perifollicular and petechial hemorrhages, gingivitis, and joint pain.

✓ Correct Answer: C. Scurvy