[A]: Wax, resin and suberin coating on the surface of plant parts reduce the rate of transpiration.
[R]: These adaptations are found mostly in xerophytes.

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

### Step-by-Step Solution:

1. **Understanding the Assertion**: The assertion states that wax, resin, and suberin coatings on the surface of plant parts reduce the rate of transpiration.
- **Explanation**: Transpiration is the process of water vapor loss from plant surfaces, primarily through stomata. The presence of waxy, resinous, or suberin layers creates a barrier that limits water loss.

2. **Analyzing the Components**: Wax, resin, and suberin are fatty substances that can coat plant surfaces.
- **Function**: These substances are hydrophobic (water-repelling), which helps in reducing the permeability of the plant surface to water, thus minimizing transpiration.

3. **Understanding the Reason**: The reason states that these adaptations are mostly found in xerophytes.
- **Definition of Xerophytes**: Xerophytes are plants adapted to survive in environments with limited water availability, such as deserts.

4. **Linking Assertion and Reason**: Xerophytes exhibit various adaptations to conserve water, including:
- Sunken stomata to reduce water loss.
- Reduced leaf surface area (e.g., leaves modified into spines).
- Thickened cuticles and coatings of wax, resin, or suberin to further limit transpiration.

5. **Conclusion**: Both the assertion and reason are correct statements. The adaptations mentioned in the reason (xerophytes) provide a valid explanation for the assertion regarding the reduction of transpiration due to wax, resin, and suberin coatings.

6. **Final Answer**: Therefore, both the assertion (A) and the reason (R) are true, and the reason is the correct explanation of the assertion.