Adiantum is called "walking fern" due to

Options

A. Power of locomotion
B. Vegetative reproduction
C. Motile antherozoites
D. All the above

Answer

### Step-by-Step Solution:

1. **Understanding Adiantum**:
- Adiantum is a genus of ferns commonly known as "maidenhair ferns." It belongs to the group of plants called pteridophytes, which are the first plants to have vascular tissues.

2. **Defining "Walking Fern"**:
- The term "walking fern" refers to the way Adiantum reproduces. The leaves of the Adiantum plant can arch downwards and touch the ground.

3. **Mechanism of Reproduction**:
- When the arching leaves of the Adiantum touch the ground, they can produce new plantlets at the points of contact. This process is a form of vegetative reproduction.

4. **Conclusion**:
- The reason Adiantum is called "walking fern" is due to its ability to reproduce vegetatively by having its leaves touch the ground and form new plants. Thus, the correct answer to the question is that Adiantum is called "walking fern" due to vegetative reproduction.