A : Xerophytes have high water retaining capacity .
R: They have high OP .

Options

A. If both Assertion & Reason are true and the reason is the correct explanation of the assertion, then mark (1)
B. If both Assertion & Reason are true but the reason is not the correct explanation of the assertion, then mark (2)
C. Assertion is true statement but Reason is false, then mark (3)
D. If both Assertion and Reason are false statements , then mark (4)

Answer

To solve the question regarding the assertion and reason about xerophytes, we can break it down into the following steps:

### Step-by-Step Solution:

1. **Understanding the Assertion**: The assertion states that "Xerophytes have high water retaining capacity."
- **Explanation**: Xerophytes are plants that have adapted to survive in environments with very low water availability, such as deserts. They possess various adaptations that allow them to retain water efficiently.

2. **Understanding the Reason**: The reason states that "They have high osmotic pressure (OP)."
- **Explanation**: Osmotic pressure is the pressure required to prevent the flow of water across a semipermeable membrane. In xerophytes, the cell sap is highly concentrated, which leads to high osmotic pressure. This allows them to absorb water from the environment effectively.

3. **Evaluating the Truth of Both Statements**:
- Both the assertion and the reason are true. Xerophytes indeed have a high water retaining capacity, and this is due to their high osmotic pressure.

4. **Determining the Relationship**:
- The reason provided explains why the assertion is true. High osmotic pressure in xerophytes allows them to retain water, which is essential for their survival in arid conditions.

5. **Conclusion**: Since both the assertion and reason are true, and the reason correctly explains the assertion, the correct answer is option 1.

### Final Answer:
Both assertion and reason are true, and the reason is the correct explanation of the assertion. Therefore, the answer is **1**.

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