Salvarsan is arsenic containing drug which was first used for the treatment of `"……."`

Options

A. syphilis
B. typhoid
C. meningitis
D. dysentry

Explanation

**Step-by-Step Solution:**

1. **Identify the Drug**: The drug in question is Salvarsan, which is known to contain arsenic.

2. **Determine the Disease**: The question asks for the first disease for which Salvarsan was used as a treatment.

3. **Review the Options**: The options provided are:
- 1) Syphilis
- 2) Typhoid
- 3) Meningitis
- 4) Dysentery

4. **Recall Historical Context**: Salvarsan was developed by Paul Ehrlich, who was investigating arsenic-based compounds to create less toxic treatments for infectious diseases.

5. **Identify the Correct Answer**: Salvarsan was first effectively used to treat syphilis, which is an infectious disease caused by the bacterium Treponema pallidum.

6. **Conclusion**: Therefore, the correct answer to the question is option 1, syphilis.

---