Chancroid is caused by

Options

A. Neisseria gonorrhoeae
B. Trepanema pallidum
C. Haemophilus ducreyi
D. Human papilloma virus

Answer

### Step-by-Step Solution

1. **Understanding the Question**: The question asks for the causative organism of Chancroid. Chancroid is a sexually transmitted disease characterized by painful ulcers.

2. **Reviewing Options**: The options provided include:
- Neisseria gonorrhea
- Treponema pallidum
- Haemophilus ducreyi
- Human papillomavirus (HPV)

3. **Analyzing Each Option**:
- **Neisseria gonorrhea**: This organism is known to cause gonorrhea, which is a different sexually transmitted infection. Therefore, this option is incorrect.
- **Treponema pallidum**: This is the causative agent of syphilis, another sexually transmitted disease. It does not cause Chancroid, making this option incorrect as well.
- **Haemophilus ducreyi**: This is the correct causative organism for Chancroid. It leads to the formation of painful ulcers at the site of infection, typically the external genitalia.
- **Human papillomavirus (HPV)**: This virus is responsible for genital warts, which is also a sexually transmitted infection but not Chancroid. Thus, this option is incorrect.

4. **Conclusion**: After analyzing all the options, the correct answer is **Haemophilus ducreyi**, as it is the organism that causes Chancroid.

### Final Answer
Chancroid is caused by **Haemophilus ducreyi**.

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