Assertion : Bryophytes are of great ecological importance.
Reason: Bryophytes help in colonisation (succession) on bare rocks/soil.

Options

A. If both assertion and Reason are true and the reason is a correct explanation of the assertion.
B. If both Assertion and Reason are true but Reason is not a correct explanation of the Assertion.
C. If Assertion is True but the Reason is False.
D. If both Assertion and Reason are False.

Answer

### Step-by-Step Solution

1. **Understanding the Assertion**: The assertion states that "Bryophytes are of great ecological importance." This is true as bryophytes, which include mosses and liverworts, play significant roles in ecosystems.

2. **Identifying the Role of Bryophytes**: Bryophytes are often referred to as the pioneers of land plants. They are the first organisms to colonize barren environments, such as bare rocks and soil.

3. **Ecological Importance**:
- Bryophytes contribute to ecological succession by preparing the environment for other plants. They create conditions that allow for the growth of more complex plants.
- They help in soil formation by breaking down rocks through the secretion of organic acids, which dissolve minerals and contribute to soil development.

4. **Reasoning Behind the Assertion**: The reason states that "Bryophytes help in colonization (succession) on bare rocks/soil." This is also true. Bryophytes not only colonize these areas but also facilitate the establishment of other plant species.

5. **Connection Between Assertion and Reason**: The reason provides a valid explanation for the assertion. Since bryophytes are crucial in the process of ecological succession, their role in colonizing bare rocks and soil highlights their ecological importance.

6. **Conclusion**: Both the assertion and the reason are true, and the reason correctly explains the assertion. Therefore, we conclude that bryophytes are indeed of great ecological importance due to their role in colonization and soil formation.

### Summary
- **Assertion**: True
- **Reason**: True
- **Explanation**: The reason justifies the assertion.