## Core Concept
Rickets is a disease caused by vitamin D deficiency, leading to softening of bones in children. It results from impaired mineralization of bone tissue due to lack of vitamin D, calcium, or phosphate. The condition is characterized by various clinical and radiological features.

## Why the Correct Answer is Right
The correct answer, , is associated with a condition that is not typically seen in rickets. Rickets primarily affects bone mineralization, leading to features like bowed legs, delayed growth, and specific radiographic changes.

## Why Each Wrong Option is Incorrect
* **Option A:** is a feature of rickets. In rickets, there is a characteristic cupping and fraying of the metaphyses of long bones on radiographs, which is a hallmark of the disease.
* **Option B:** is also seen in rickets. The condition often presents with bowed legs (genu varum or genu valgum), which is a result of the softening of bones.
* **Option D:** is associated with rickets as well. Rachitic rosary, which refers to the prominent knobs of bone at the costochondral junctions of the ribs, is a classic clinical feature.

## Clinical Pearl / High-Yield Fact
A key clinical feature to remember in rickets is the presence of **rachitic rosary** and **cupping and fraying of metaphyses** on X-rays. These are high-yield facts for exams.

## Correct Answer: D. Tetany