Which one of the following statements is not true ?

Options

A. Ampicillin is a natural antibiotic
B. Aspirin is both analgesic and antipyretic
C. sulphadiazine is a synthetic antibacterial drug
D. Some disinfectants can be used as antiseptics

Answer

To solve the question "Which one of the following statements is not true?", we will analyze each option provided and determine its validity.

### Step-by-Step Solution:

1. **Analyze Option A: Ampicillin is a natural antibiotic.**
- Ampicillin is known to be a semi-synthetic derivative of penicillin, which means it is not a natural antibiotic. Therefore, this statement is **not true**.

2. **Analyze Option B: Aspirin is both analgesic and antipyretic.**
- Aspirin is indeed classified as both an analgesic (pain reliever) and an antipyretic (fever reducer). This statement is **true**.

3. **Analyze Option C: Sulfadiazine is a synthetic antibacterial drug.**
- Sulfadiazine is a synthetic drug used to treat bacterial infections. This statement is also **true**.

4. **Analyze Option D: Some disinfectants can be used as antiseptics.**
- Disinfectants are typically used on non-living surfaces, while antiseptics are used on living tissues. However, some disinfectants can be diluted and used as antiseptics. This statement is **true**.

### Conclusion:
After analyzing all options, we find that the statement in **Option A** is the only one that is **not true**.

### Final Answer:
The statement that is not true is **Option A: Ampicillin is a natural antibiotic.**

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