[A]: The vascular cambium is absent in monocots.
[R]: The monocots never show secondary growth

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 regarding the assertion and reason statements about monocots and vascular cambium, we can break it down into clear steps:

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that "The vascular cambium is absent in monocots."
- Vascular cambium is a type of meristematic tissue that is responsible for secondary growth in plants. It is found between the xylem and phloem in dicots.

2. **Understanding the Reason**:
- The reason states that "The monocots never show secondary growth."
- Secondary growth refers to the increase in thickness or girth of the plant stem or root, which is facilitated by the vascular cambium.

3. **Analyzing the Relationship**:
- Since monocots lack vascular cambium, they cannot undergo secondary growth. This means that the absence of vascular cambium directly leads to the inability of monocots to exhibit secondary growth.

4. **Conclusion**:
- Both the assertion and the reason are true statements. The reason correctly explains the assertion because the absence of vascular cambium in monocots is the reason they do not show secondary growth.

5. **Final Answer**:
- Therefore, the answer is that both the assertion and reason are true, and the reason is the correct explanation for the assertion.