Plague is caused by

Options

A. Diplococous pneumoniae
B. Yersinia pestis
C. Corynebacterium diphtheriae
D. All of the above

Answer

**Step-by-Step Solution:**

1. **Identify the Question**: The question asks about the causative agent of plague.

2. **Examine the Options**: The options provided are:
- A) Diplococcus pneumoniae
- B) Ebsenia pestis
- C) Corynebacterium diphtheriae
- D) All of the above

3. **Analyze Each Option**:
- **Option A: Diplococcus pneumoniae** - This bacterium is known to cause pneumonia, not plague.
- **Option B: Ebsenia pestis** - This is a typographical error; the correct name is *Yersinia pestis*, which is the bacterium responsible for causing plague.
- **Option C: Corynebacterium diphtheriae** - This bacterium causes diphtheria, not plague.
- **Option D: All of the above** - Since only *Yersinia pestis* causes plague, this option is incorrect.

4. **Conclusion**: The correct answer is *Yersinia pestis*, which is the causative agent of plague.

5. **Final Answer**: Plague is caused by *Yersinia pestis*.

---