Assertion :- Main function of stem is spreading out branches bearing leaves, flowers and fruits.
Reason :- Usually monocot stem is differentiated into nodes and internodes.

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

To solve the assertion-reason question, we need to analyze both the assertion and the reason provided.

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that the main function of the stem is to spread out branches that bear leaves, flowers, and fruits.
- This is correct because the stem serves as the main axis of the plant, supporting the branches and facilitating the growth of leaves, flowers, and fruits.

2. **Understanding the Reason**:
- The reason given is that usually, monocot stems are differentiated into nodes and internodes.
- This statement is also correct. In monocots, the stem is characterized by the presence of nodes (where leaves are attached) and internodes (the segments between nodes).

3. **Evaluating the Connection**:
- While both the assertion and reason are correct, we need to determine if the reason is the correct explanation for the assertion.
- The assertion focuses on the functions of the stem (spreading out branches and supporting leaves, flowers, and fruits), while the reason describes a structural characteristic of monocot stems.

4. **Conclusion**:
- Since the reason does not explain why the main function of the stem is to spread out branches, it is not a correct explanation of the assertion.
- Therefore, the final answer is: Both the assertion and reason are correct, but the reason is not a correct explanation of the assertion.

### Final Answer:
- Both the assertion and reason are correct, but the reason is not a correct explanation of the assertion.