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

Options

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

Answer

To solve the question "Which of the following STD is not caused by a bacterium?", we will analyze each option provided.

### Step-by-Step Solution:

1. **Identify the Options**: The options given are:
- A) Chlamydia
- B) Gonorrhea
- C) Syphilis
- D) Genital herpes

2. **Evaluate Each Option**:
- **Option A: Chlamydia**
- Chlamydia is caused by the bacterium *Chlamydia trachomatis*. Therefore, it is caused by a bacterium.

- **Option B: Gonorrhea**
- Gonorrhea is caused by the bacterium *Neisseria gonorrhoeae*. Thus, it is also caused by a bacterium.

- **Option C: Syphilis**
- Syphilis is caused by the bacterium *Treponema pallidum*. Therefore, it is caused by a bacterium as well.

- **Option D: Genital herpes**
- Genital herpes is caused by the human papillomavirus (HPV), which is a virus. Hence, it is not caused by a bacterium.

3. **Conclusion**: Based on the analysis, the only option that is not caused by a bacterium is **D) Genital herpes**.

### Final Answer:
The STD that is not caused by a bacterium is **D) Genital herpes**.

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