AIDS is caused by HIV that principally infects

Options

A. All lymphocytes
B. Activator B-cells
C. T-4 lymphocytes
D. Cytotoxic T-cells

Answer

### Step-by-Step Solution:

1. **Understanding AIDS and HIV**:
- AIDS stands for Acquired Immunodeficiency Syndrome, which is caused by the Human Immunodeficiency Virus (HIV).
- HIV is a virus that attacks the immune system, specifically targeting certain types of white blood cells.

2. **Identifying the Target Cells**:
- The primary cells that HIV infects are known as T lymphocytes, specifically the T helper cells, which are also referred to as T4 lymphocytes.
- These cells play a crucial role in the immune response by activating other immune cells, including B cells and macrophages.

3. **Impact of HIV on the Immune System**:
- When HIV infects and destroys T4 lymphocytes, the immune system becomes compromised.
- This leads to a decrease in the body’s ability to fight off infections and diseases, making the individual vulnerable to opportunistic infections.

4. **Conclusion**:
- Therefore, the answer to the question is that AIDS is caused by HIV, which principally infects T4 lymphocytes (T helper cells).