Device for self - pollination is :

Options

A. Hetrostyly
B. Dicliny
C. Unisexuality
D. none of the above

Answer

To solve the question "Device for self-pollination is:", we need to analyze the provided options and determine which one, if any, supports self-pollination.

### Step-by-Step Solution:

1. **Understanding Pollination**:
- Pollination is the process where pollen grains are transferred from the anther (male part) to the stigma (female part) of a flower. It can occur in two ways: self-pollination and cross-pollination.
- **Self-pollination** occurs when pollen from the same flower fertilizes its own stigma.
- **Cross-pollination** occurs when pollen is transferred from the anther of one flower to the stigma of another flower.

2. **Analyzing the Options**:
- **Option A: Heterostyly**: This refers to a condition where flowers have styles of different lengths. This condition usually promotes cross-pollination as it encourages pollen transfer between flowers of different heights.
- **Option B: Dichogamy**: This term refers to the maturation of male and female reproductive organs at different times. It also promotes cross-pollination by preventing self-fertilization.
- **Option C: Unisexuality**: This means that a flower has either male or female reproductive parts, not both. This condition also does not support self-pollination as it requires another flower for fertilization.
- **Option D: None of the above**: This option suggests that none of the previous conditions support self-pollination.

3. **Conclusion**:
- Since heterostyly, dichogamy, and unisexuality do not facilitate self-pollination, the correct answer is **D: None of the above**.

### Final Answer:
The device for self-pollination is **D: None of the above**.