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

1. Arthritis

2. Osteoporosis

3. Rickets

4. Atherosclerosis

(d) Atherosclerosis also known as ateriosclerotic vascular disease, where arteries wall get thickens as a result of invasion and accumulation of WBC, containing both livings active WBCs (white blood Cells) and remnants of dead WBC's along with cholesterol and triglycerides. Remaining diseases, i.e., arthritis, osteoporosis and rickets are bone disorders.