Which of the following STD is not caused by a bacterium ?

Options

A. Chlamydia
B. Gonorrhea
C. Syphilis
D. Genital herpes

Answer

To determine which of the following STDs is not caused by a bacterium, we can analyze the options provided:

1. **Chlamydia**: This is caused by the bacterium *Chlamydia trachomatis*. Therefore, it is caused by a bacterium.

2. **Gonorrhea**: This STD is caused by the bacterium *Neisseria gonorrhoeae*. Thus, it is also caused by a bacterium.

3. **Syphilis**: This is caused by the bacterium *Treponema pallidum*. Hence, it is caused by a bacterium as well.

4. **Genital Herpes**: This STD is caused by the herpes simplex virus (HSV), specifically HSV-1 and HSV-2. Therefore, it is not caused by a bacterium.

Based on this analysis, the STD that is not caused by a bacterium is **Genital Herpes**.

### Summary of the Solution:
- Chlamydia: Caused by a bacterium.
- Gonorrhea: Caused by a bacterium.
- Syphilis: Caused by a bacterium.
- Genital Herpes: Caused by a virus (not a bacterium).

**Correct Answer: Genital Herpes**

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