Explanation:

Osteomalacia is a condition characterized by the softening of bones, primarily due to impaired bone mineralization. This condition is predominantly caused by a severe deficiency of Vitamin D, which is crucial for the absorption of calcium and phosphate in the intestines and their subsequent incorporation into bone tissue. Option (2) 'Vitamin D' is correct. Option (1) 'Vitamin C' deficiency leads to scurvy. Option (3) 'Vitamin K' deficiency can cause impaired blood clotting and bleeding disorders. Option (4) 'Vitamin H', also known as Biotin, deficiency can lead to dermatitis, hair loss, and neurological symptoms. Therefore, Osteomalacia is directly linked to Vitamin D deficiency.