[A]: Aerenchyma is a characteristic of litho- phyte.
[R]: It is a specialised tissue for buoyancy in lithophytes

Options

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

Answer

To solve the question, we need to evaluate the assertion and reason provided regarding aerenchyma and lithophytes.

### Step-by-Step Solution:

1. **Understanding Lithophytes**:
- Lithophytes are plants that grow on rocky surfaces or bare rocks. They are adapted to survive in harsh, dry environments with limited nutrients and water.

2. **Understanding Aerenchyma**:
- Aerenchyma is a specialized type of plant tissue characterized by large air spaces (intercellular spaces) that facilitate gas exchange and provide buoyancy. It is commonly found in aquatic plants (hydrophytes) to help them float.

3. **Analyzing the Assertion (A)**:
- The assertion states that "Aerenchyma is a characteristic of lithophytes."
- This statement is **false** because aerenchyma is not a characteristic of lithophytes; it is primarily found in hydrophytes.

4. **Analyzing the Reason (R)**:
- The reason states that "It is a specialized tissue for buoyancy in lithophytes."
- This statement is also **false** because, while aerenchyma does serve the function of buoyancy, it is not associated with lithophytes but rather with hydrophytes.

5. **Conclusion**:
- Since both the assertion and the reason are false, the correct answer is that both A and R are false.

### Final Answer:
Both A and R are false.

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