The logic followed is: For this question, the relation of Psoriasis : Skin is given below-Psoriasis is a skin disease that causes red, itchy scaly patches, most commonly on the knees, elbows, trunk, and scalp. Psoriasis is a common, long-term (chronic) disease with no cure. Similarly, Rickets is a bone disease due to the softening and weakening of bones in children, usually because of an extreme and prolonged vitamin D deficiency.Hence, Option (4) is correct.