Vivipary may be described as:

Options

A. germination of seed with cotyledons above the soil
B. germination of seed with cotyledons under the soil
C. formation of a fruit without pollination
D. development of a seedling within an attached fruit

Explanation

**Step-by-Step Solution:**

1. **Understanding Vivipary**: Vivipary is a specific type of germination where seeds begin to germinate while still attached to the parent plant. This process is commonly observed in certain plants, particularly mangroves, which thrive in saline and marshy environments.

2. **Identifying Characteristics**: In viviparous plants, the seeds do not fall off the parent plant immediately after maturation. Instead, they develop into seedlings while still connected to the parent, allowing them to grow in a suitable environment.

3. **Analyzing the Options**:
- **Option A**: Germination of seed with cotyledons above the soil - This is incorrect as it does not describe vivipary.
- **Option B**: Germination of seed with cotyledons under the soil - This is also incorrect for vivipary.
- **Option C**: Formation of root without pollination - This is not relevant to the concept of vivipary.
- **Option D**: Development of seedling within an attached root - This accurately describes vivipary, as it indicates that the seedling develops while still attached to the parent plant.

4. **Conclusion**: The correct description of vivipary is "Development of seedling within an attached root."

**Final Answer**: Vivipary may be described as the development of seedling within an attached root.

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