**Core Concept**
Rickets is a disease caused by vitamin D deficiency, leading to softening and weakening of bones in infants and children. It results from impaired mineralization of osteoid tissue, causing deformities and skeletal abnormalities.

**Why the Correct Answer is Right**
Bow legs, or genu varum, is typically associated with rickets' counterpart, osteomalacia, which affects adults. In infants, rickets more commonly presents with genu varum's opposite, genu valgum (knock knees). The mechanism behind rickets involves impaired osteoid mineralization, which affects the growth plates and leads to characteristic deformities.

**Why Each Wrong Option is Incorrect**
**Option A:** Cranitabes, or softening of the skull bones, is indeed a manifestation of rickets, as it reflects the impaired mineralization of osteoid tissue.

**Option B:** Widened fontanelles are a hallmark of rickets, as the softening of the bones affects the sutures and fontanelles, leading to an increased intracranial pressure and widened fontanelles.

**Option C:** Rachitic rosary, a beading of the ribs, is a characteristic feature of rickets. This occurs due to the accumulation of osteoid tissue at the growth plates, which causes the ribs to become enlarged and prominent.

**Clinical Pearl / High-Yield Fact**
Rickets is often associated with other signs of vitamin D deficiency, such as alopecia, anemia, and hypocalcemic seizures. Early recognition and treatment are crucial to prevent long-term skeletal deformities and complications.

**✓ Correct Answer: D. Bow legs**