Assertion : The fimbriae are elongated tubular structures made of a special protein.
Reason : The pili are small bristle like fibres sprouting out of the cell.

Options

A. If both assertion and reason are true and reason is the correct explanation of assertion.
B. If both assertion and reason are true but reason is not the correct explanation of assertion.
C. If assertion is true but reason is false.
D. If both assertion and reason are false.

Explanation

### Step-by-Step Solution:

1. **Understanding the Assertion**: The assertion states that "The fimbriae are elongated tubular structures made of a special protein."
- Fimbriae are indeed surface structures found on bacteria, but they are not elongated tubular structures; rather, they are short, hair-like projections.

2. **Understanding the Reason**: The reason states that "The pili are small bristle-like fibres sprouting out of the cell."
- This is incorrect as well. Pili are actually longer than fimbriae and are tubular structures. They are involved in processes such as conjugation (a form of bacterial mating).

3. **Analyzing Both Statements**:
- Both the assertion and reason are false based on the definitions and characteristics of fimbriae and pili.
- Fimbriae are not elongated tubular structures; they are more like bristle-like fibers.
- Pili are not small bristle-like fibers; they are longer and serve different functions.

4. **Conclusion**: Since both the assertion and the reason are false, the correct answer is that both assertion and reason are false.

### Final Answer:
Both assertion and reason are false.

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