Assertion : AIDS is a disorder caused by HIV.
Reason : HIV is a virus that damage the immune system of its host.

Options

A. Both assertion and reason are true and reason is the correct explanation of assertion
B. Both assertion and reason are true, but reason is not correct explanation of assertion
C. Assertion is true, but reason is false
D. Assertion is false, but reason is true

Explanation

### Step-by-Step Solution:

1. **Understanding the Assertion**: The assertion states that "AIDS is a disorder caused by HIV."
- **Explanation**: This is true. AIDS (Acquired Immunodeficiency Syndrome) is indeed a disorder that results from infection with the Human Immunodeficiency Virus (HIV).

2. **Understanding the Reason**: The reason provided is "HIV is a virus that damages the immune system of its host."
- **Explanation**: This statement is also true. HIV specifically targets and destroys CD4 T-lymphocytes, which are crucial for the immune response, thereby compromising the immune system.

3. **Analyzing the Relationship**: Now, we need to determine if the reason correctly explains the assertion.
- **Explanation**: Since HIV damages the immune system, leading to the development of AIDS, the reason does indeed provide a correct explanation for the assertion.

4. **Conclusion**: Both the assertion and the reason are true, and the reason is the correct explanation of the assertion.

5. **Selecting the Correct Option**: Based on the analysis, the correct option would be: "Both assertion and reason are true, and the reason is the correct explanation of the assertion."