As Stilt roots grow obliquely into soil.
R Respiratory roots are negatively geotropic.

Options

A. If both As and R are correct and R is correct explanation of As
B. If both As and R are correct but R is not correct explanation of As
C. If As is correct, R is wrong
D. If both As and R are wrong.

Answer

To solve the question regarding stilt roots and respiratory roots, we will analyze the assertion and reason provided, and determine their correctness and relationship.

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that "stilt roots grow obliquely into the soil."
- Stilt roots are specialized roots that arise from the lower nodes of the stem and grow obliquely into the soil to provide support to the plant.
- Examples of plants with stilt roots include maize and sugarcane.
- **Conclusion**: The assertion is correct.

2. **Understanding the Reason**:
- The reason states that "respiratory roots are negatively geotropic."
- Respiratory roots, also known as pneumatophores, are specialized roots that grow upwards, above the soil or water surface, to facilitate gas exchange.
- Negatively geotropic means that these roots grow against the force of gravity.
- **Conclusion**: The reason is also correct.

3. **Analyzing the Relationship**:
- The assertion discusses stilt roots, while the reason discusses respiratory roots.
- Although both statements are correct, they refer to different types of root modifications and do not explain each other.
- **Conclusion**: The reason is not a correct explanation of the assertion.

4. **Final Answer**:
- Since both the assertion and reason are correct, but the reason does not explain the assertion, the correct option is: "Both assertion and reason are correct, but reason is not the correct explanation of assertion."