Assertion :- In some xerophytic plants stem becomes green , flat,leaf like and leaves are modified into spines .
Reason :-In xerophytic areas rate of transpiration is high , so plants develop various adaptions to minimize transpiration.

Options

A. If both Assertion & Reason are True & Reason is a correct explanation of the Assertion.
B. If both Assertion & Reason are True & the Reason is a correct explanation of the Assertion.
C. If Assertion is True but the Reason is False.
D. If both Assertion & Reason are false.

Answer

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that in some xerophytic plants, the stem becomes green, flat, leaf-like, and the leaves are modified into spines.
- Xerophytic plants are adapted to survive in environments with limited water, such as deserts.

2. **Analyzing the Reason**:
- The reason provided explains that in xerophytic areas, the rate of transpiration is high, prompting plants to develop adaptations to minimize water loss.
- Transpiration is the process by which water evaporates from the plant's surface, primarily through stomata in the leaves.

3. **Connecting Assertion and Reason**:
- The adaptation of the stem becoming green and leaf-like allows for photosynthesis to occur, compensating for the loss of leaves that have been modified into spines.
- The modification of leaves into spines reduces the surface area through which transpiration can occur, thereby conserving water.

4. **Evaluating the Truth of Both Statements**:
- Both the assertion and reason are true. The stem's adaptation allows for photosynthesis while minimizing water loss, and the modification of leaves into spines is a direct response to high transpiration rates.

5. **Determining the Relationship**:
- The reason provided is indeed the correct explanation for the assertion. The adaptations of xerophytic plants are a direct response to the environmental conditions they face, specifically the high rate of transpiration.

6. **Conclusion**:
- Therefore, both the assertion and reason are true, and the reason is the correct explanation of the assertion.

### Final Answer:
Both the assertion and reason are true, and the reason is the correct explanation of the assertion.

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