Assertion :- Hydrogen bonds between base pairs is the only mean to stabilise helical structure.
Reason : Plane of one base pair stacks over other have no role in stability of DNA helices.

Options

A. If both Assertion & Reason are True & the Reason is a correct explanation of the Assertion.
B. If both Assertion & Reason are trur but Reason is not a correct explanation of the Assertion.
C. If Assertion is True but the Reason is False.
D. If both Assertion & Reason are false.

Answer

To analyze the assertion and reason statements provided in the question, we can break down the solution into the following steps:

### Step-by-Step Solution:

1. **Understanding the Assertion**: The assertion states that "Hydrogen bonds between base pairs is the only means to stabilize the helical structure."
- **Analysis**: This statement is misleading. While hydrogen bonds do contribute to the stability of the DNA double helix, they are not the only means of stabilization.

2. **Understanding the Reason**: The reason states that "The plane of one base pair stacks over another has no role in the stability of DNA helices."
- **Analysis**: This statement is also incorrect. The stacking of base pairs (base stacking interactions) plays a significant role in the stability of the DNA structure. These interactions help stabilize the helical structure through hydrophobic interactions and van der Waals forces.

3. **Conclusion on Both Statements**:
- Since the assertion is false (hydrogen bonds are not the only means of stabilization) and the reason is also false (base stacking does contribute to stability), we conclude that both statements are incorrect.

4. **Final Answer**: Therefore, the correct answer is that both the assertion and the reason are false.