Common cold is not cured by antibiotics because it is

Options

A. Caused by a virus
B. Caused by a Gram-positive bacterium
C. Caused by a Gram-negative bacterium
D. Not an infectious disease

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks why common cold is not cured by antibiotics.

2. **Identifying the Cause of Common Cold**: Common cold is primarily caused by viruses. This is a crucial point to note because antibiotics are designed to combat bacterial infections, not viral infections.

3. **Reviewing the Options**:
- **Option A**: Caused by a virus - This is correct.
- **Option B**: Caused by a gram-positive bacterium - This is incorrect because common cold is not caused by bacteria.
- **Option C**: Caused by a gram-negative bacterium - This is also incorrect for the same reason as option B.
- **Option D**: Not an infectious disease - This is incorrect as common cold is indeed an infectious disease.

4. **Conclusion**: Since common cold is caused by a virus, antibiotics, which are ineffective against viruses, cannot cure it. Therefore, the correct answer is **Option A: caused by a virus**.

5. **Additional Information**: Common cold is an infectious disease affecting the upper respiratory tract, and symptoms include sneezing, runny nose, cough, and sore throat. Treatment focuses on alleviating symptoms rather than curing the infection.

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