Assertion : Ginger has a prostrate-growing rhizome
Reason : Shoot growth is not effected by gravity.

Options

A. If both assertion and reason are true and reason is the correct explaination of assertion
B. If both assertion and reason are true but reason is not correct explaination of assertion
C. If assertion is true but reason is false
D. If both assertion and reason are false.

Explanation

To solve the assertion-reason question regarding ginger and its rhizome, we can break down the statements step by step.

### Step-by-Step Solution:

1. **Understanding the Assertion:**
- The assertion states that "Ginger has a prostrate-growing rhizome."
- A rhizome is a type of underground stem that grows horizontally. In ginger, this rhizome is indeed prostrate, meaning it grows along the ground.

2. **Understanding the Reason:**
- The reason states that "Shoot growth is not affected by gravity."
- In botany, shoot growth (the growth of stems and leaves) is generally considered to be positively phototropic (growing towards light) and negatively gravitropic (growing away from gravity). This means that while gravity does influence growth direction, the shoots can grow in a direction that is not strictly determined by gravity.

3. **Evaluating the Truth of Each Statement:**
- Both the assertion and the reason are true:
- The assertion about ginger's rhizome being prostrate is correct.
- The reason about shoot growth being independent of gravity is also correct.

4. **Determining the Relationship:**
- The next step is to determine whether the reason correctly explains the assertion.
- While both statements are true, the reason does not directly explain why ginger has a prostrate-growing rhizome. The growth pattern of the rhizome is more related to its adaptation and function rather than the effect of gravity on shoot growth.

5. **Conclusion:**
- Since both the assertion and reason are true, but the reason does not explain the assertion, the correct answer is: **B** (Both assertion and reason are true, but reason is not the correct explanation of the assertion).