**Core Concept**
Rickets is a disease caused by vitamin D deficiency, leading to softening and weakening of bones in infants and children. This occurs due to impaired mineralization of osteoid tissue, resulting from a lack of calcium and phosphate. Vitamin D plays a crucial role in the absorption of calcium from the gut, and its deficiency disrupts this process.

**Why the Correct Answer is Right**
The correct answer is related to the clinical presentation of rickets. Rickets typically presents with bowing of the legs, softening of the skull bones, and delayed closure of the fontanelles. This is due to the impaired mineralization of osteoid tissue, leading to weakened bones. The symptoms are a result of the body's attempt to adapt to the lack of calcium and phosphate, leading to characteristic deformities.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because rickets can indeed present with **bowing of the legs**, which is a classic symptom of the disease. This occurs due to the weakened state of the bones, leading to deformities.

**Option B:** This option is incorrect because **softening of the skull bones** is a common presentation of rickets. The softened bones of the skull can lead to a variety of complications, including increased intracranial pressure.

**Option C:** This option is incorrect because **delayed closure of the fontanelles** is a common feature of rickets. The softened bones of the skull can lead to delayed closure of the fontanelles, which is a hallmark of the disease.

**Clinical Pearl / High-Yield Fact**
Rickets is a preventable disease, and its prevention relies on adequate vitamin D supplementation, especially in areas with limited sunlight. Vitamin D deficiency can lead to a range of complications, including osteomalacia in adults and rickets in children.

**Correct Answer: A.**