Selaginella has a tendency to form seed, called seed habit because it follows

Options

A. Retention of megaspore permanently inside the megasporangium
B. Heterospory
C. Both (A) and (B)
D. None of the above

Answer

To solve the question regarding Selaginella and its tendency to form seeds, we need to analyze the options provided and understand the concepts involved.

### Step-by-Step Solution:

1. **Understanding Selaginella**:
- Selaginella is a genus of plants that belongs to the group known as pteridophytes. Pteridophytes are vascular plants that reproduce via spores rather than seeds.

**Hint**: Remember that Selaginella is a pteridophyte, which is crucial for understanding its reproductive strategies.

2. **Identifying the Seed Habit**:
- The term "seed habit" refers to the characteristics that lead to the formation of seeds. In the context of Selaginella, two main features contribute to this tendency.

3. **Retention of Megaspore**:
- The first feature is the retention of the megaspore within the megasporangium. This means that instead of being released into the environment, the megaspore remains inside the structure where it is formed. This retention allows for the development of the female gametophyte, which is a significant step towards seed formation.

**Hint**: Focus on how the retention of the megaspore contributes to the development of the female gametophyte.

4. **Heterospory**:
- The second feature is heterospory, which refers to the production of two different types of spores: megaspores (larger) and microspores (smaller). This differentiation is important because it leads to the formation of male and female gametophytes, which is essential for sexual reproduction.

**Hint**: Consider how having two types of spores (heterospory) is a precursor to seed formation.

5. **Combining the Features**:
- Both the retention of the megaspore and the presence of heterospory are crucial for the development of the seed habit in Selaginella. Therefore, the correct answer to the question is that Selaginella exhibits seed habit because it follows both A (retention of megaspore) and B (heterospory).

**Hint**: Remember that both features are interconnected and contribute to the overall seed habit.

### Final Answer:
The correct answer is **third option: both A and B**. Selaginella has a tendency to form seeds because it exhibits both the retention of the megaspore inside the megasporangium and heterospory.