The correct answer is option 2: Rickets.

Rickets is a disease that occurs due to a deficiency of Vitamin D, calcium, or phosphate in the body. Vitamin D is essential for the absorption of calcium and phosphate from the diet, and its deficiency can lead to weak and soft bones in children, causing symptoms like bowed legs, delayed growth, and muscle weakness.

Polio, option 1, is caused by a viral infection, and scurvy, option 3, is caused by a deficiency of Vitamin C. Goitre, option 4, refers to the enlargement of the thyroid gland and is usually caused by iodine deficiency. It is important to note that while these diseases can also have nutritional factors, they are not specifically caused by a deficiency of Vitamin D.