Assertion (A) :. Subaerial modifications participate in vegetative reproduction
Reason (R ) :. They store food and water

Options

A. A and R are true and R is not correct explanation of A
B. A and R are true but R is not correct explanation of A
C. A is true , R is false
D. A is false, R is true

Answer

### Step-by-Step Solution:

1. **Understanding the Assertion**: The assertion states that "Subaerial modifications participate in vegetative reproduction."
- Subaerial modifications refer to parts of the plant that are partially above the ground. Examples include runners, stolons, and certain types of stems.

2. **Understanding the Reason**: The reason provided is "They store food and water."
- This statement suggests that subaerial modifications are primarily for storage purposes, which is typically associated with underground modifications like rhizomes, bulbs, and corms.

3. **Evaluating the Assertion**:
- Subaerial modifications do indeed participate in vegetative reproduction. For example, runners (like those of strawberries) can produce new plants at nodes, and stolons can also give rise to new shoots.

4. **Evaluating the Reason**:
- While it is true that some plant structures store food and water, subaerial modifications are not primarily known for this function. Instead, they are more involved in the reproduction process. The storage function is more characteristic of underground modifications.

5. **Conclusion**:
- The assertion is true because subaerial modifications do participate in vegetative reproduction.
- The reason is false because subaerial modifications are not primarily for food and water storage; that function is more relevant to underground modifications.

6. **Final Answer**: The correct option is: "Assertion is true, reason is false."