**Core Concept**
This question tests the student's knowledge of a rare bleeding disorder characterized by poor wound healing, perifollicular hemorrhages, and sharp and painful swellings at the costochondral junction of ribs. The underlying principle involves a deficiency in a specific clotting factor.

**Why the Correct Answer is Right**
The child's symptoms suggest a diagnosis of scurvy, a disease caused by vitamin C deficiency. Vitamin C is essential for the production of collagen, a protein that gives structure to skin, bones, and connective tissue. A deficiency in vitamin C leads to impaired collagen synthesis, resulting in the characteristic symptoms of scurvy, including poor wound healing, perifollicular hemorrhages, and joint pain. The body's inability to produce sufficient collagen also affects the formation of new bone tissue, leading to the painful swellings at the costochondral junction of ribs.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is not relevant to the treatment of scurvy.
* **Option B:** This option may be a treatment for other bleeding disorders, but it is not the recommended treatment for scurvy.
* **Option C:** This option is incorrect because scurvy is caused by a deficiency in vitamin C, not an excess of vitamin C.
* **Option D:** This option is incorrect because scurvy is not caused by a deficiency in vitamin K.

**Clinical Pearl / High-Yield Fact**
Scurvy is a classic example of a disease caused by a dietary deficiency, and it can be prevented by consuming foods rich in vitamin C, such as citrus fruits, leafy greens, and bell peppers.

**Correct Answer:** D. Vitamin C supplementation