**Core Concept**
Collagen is a crucial protein that provides structure to skin, bones, tendons, and ligaments. Its formation depends on the presence of vitamin C (ascorbic acid), which acts as a co-factor for prolyl hydroxylase and lysyl hydroxylase enzymes. These enzymes are essential for stabilizing collagen triple helices and facilitating cross-linking between collagen molecules.

**Why the Correct Answer is Right**
Scurvy, a disease caused by vitamin C deficiency, results in impaired collagen synthesis. The lack of vitamin C impairs the activity of prolyl hydroxylase and lysyl hydroxylase, leading to the accumulation of procollagen molecules. This defect in collagen formation causes symptoms such as poor wound healing, joint pain, and skin fragility. The skin manifestations of scurvy include poor wound healing, petechiae, and easy bruising.

**Why Each Wrong Option is Incorrect**
**Option B:** Hunter's syndrome is an X-linked recessive disorder characterized by the deficiency of alpha-L-iduronidase, an enzyme involved in the breakdown of glycosaminoglycans. It does not affect collagen formation directly.
**Option C:** Marfan's syndrome is an autosomal dominant disorder caused by mutations in the FBN1 gene, which encodes fibrillin-1. Fibrillin-1 is a protein involved in the formation of elastic fibers in connective tissue, not collagen.
**Option D:** Osteogenesis imperfecta is a genetic disorder caused by mutations in the COL1A1 or COL1A2 genes, which encode the alpha-1 and alpha-2 chains of type I collagen. Although it affects collagen production, osteogenesis imperfecta is primarily characterized by bone fragility and osteoporosis, not a defect in collagen formation due to vitamin C deficiency.

**Clinical Pearl / High-Yield Fact**
Vitamin C supplementation is essential in patients with scurvy to improve collagen synthesis and facilitate wound healing. It's also crucial for patients undergoing surgery or with compromised wound healing to prevent scurvy.

✓ Correct Answer: A. Scurvy