Which one of the following is not a disorder of bone?

a) Arthritis
b) Osteoporosis
c) Rickets
d)Atherosclerosis

Ans-[D] 

Explanation- Atherosclerosis, or hardening of the arteries, is a condition in which plaque builds up inside the arteries. Plaque is made of cholesterol, fatty substances, cellular waste products, calcium and fibrin (a clotting material in the blood).