Rhizome/runner is

Options

A. Diageotropic
B. Plagio-geotropic
C. Negatively geotropic
D. Positively geotropic.

Answer

### Step-by-Step Solution:

1. **Understanding the Terms**:
- Rhizome and runner are types of underground stems that can grow horizontally.
- They are important for vegetative reproduction in plants.

2. **Defining Geotropism**:
- Geotropism refers to the growth of plant parts in response to gravity.
- It can be classified into three types:
- Positive Geotropism: Growth towards gravity (e.g., roots).
- Negative Geotropism: Growth away from gravity (e.g., stems).
- Diageotropism: Growth at a right angle (90 degrees) to the direction of gravity.

3. **Analyzing Rhizome/Runner Growth**:
- Rhizomes and runners grow horizontally, which means they are growing parallel to the earth's surface.
- Since they grow at a right angle to the gravitational pull, they exhibit diageotropic behavior.

4. **Choosing the Correct Option**:
- The question asks about the nature of rhizomes/runners.
- Given the definitions:
- Option A (Diageotropic) is correct because rhizomes and runners grow horizontally, which is at a 90-degree angle to gravity.

5. **Conclusion**:
- Therefore, the correct answer is **Option A: Diageotropic**.