Answer : 2. "Rickets"
Explanation :

1. Rickets occurs when a child's growing bones do not develop due to vitamin D deficiency.

2. Vitamin D is an essential nutrient that helps in the absorption of calcium and phosphate.

3. Symptoms of rickets include.

- Pain and tenderness in the bones of the feet and hands

- curvature in the bones of the legs

- pain in shoulders and hips

- muscle weakness

- delayed development