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

Options

A. Arthritis
B. Osteoporosis
C. Rickets
D. Atherosclerosis

Answer

To determine which of the following options is not a disorder of bone, we need to analyze each option provided:

1. **Arthritis**: This is a condition characterized by inflammation of the joints, which can involve the bones. It is indeed considered a disorder related to the bones, as it affects the joint surfaces where bones meet.

2. **Osteoporosis**: This is a bone disorder where bones become weak and brittle due to a loss of calcium and phosphate. It is directly related to bone health and is classified as a bone disorder.

3. **Rickets**: This condition is caused by a deficiency of vitamin D, leading to softening and weakening of bones in children. It is also classified as a bone disorder.

4. **Atherosclerosis**: This is a condition that involves the hardening and narrowing of the arteries due to the buildup of cholesterol and other substances in the arterial walls. It primarily affects the cardiovascular system and is not related to bone health.

Based on the analysis above, the correct answer is **atherosclerosis**, as it is not a disorder of bone.

### Step-by-Step Solution:
1. **Identify the Disorders**: List the options given and identify which are related to bone disorders.
- Arthritis: Bone-related
- Osteoporosis: Bone-related
- Rickets: Bone-related
- Atherosclerosis: Not bone-related

2. **Analyze Each Condition**: Understand the nature of each condition.
- Arthritis involves inflammation of joints (bone-related).
- Osteoporosis involves loss of bone density (bone-related).
- Rickets involves vitamin D deficiency affecting bone strength (bone-related).
- Atherosclerosis involves arterial health (not bone-related).

3. **Conclusion**: Determine which condition does not belong to the category of bone disorders.
- Atherosclerosis is the only condition that does not affect bones.

### Final Answer:
The condition that is not a disorder of bone is **atherosclerosis**.