Assertion: Lubricant reduces friction between two surfaces
Reason: Shape of rockets is streamlined to reduce frictional force.

Options

A. If both assertion and reason are true and reason is the correct explanation of assertion
B. If oth assertion and reason are true but reason is not the correct explanation of assertion
C. If assertion is true but reason is false
D. If both assertion and reason are false

Answer

### Step-by-Step Solution:

1. **Understanding the Assertion**: The assertion states that "Lubricants reduce friction between two surfaces." This is true because lubricants, such as oils and greases, fill the microscopic gaps between surfaces, creating a smoother interface that allows them to slide past each other more easily.

2. **Understanding the Reason**: The reason given is that "The shape of rockets is streamlined to reduce frictional force." This statement is also true. Streamlining reduces air resistance (a form of friction) by allowing air to flow smoothly around the object, minimizing turbulence and drag.

3. **Analyzing the Relationship**: While both the assertion and the reason are true, we need to determine if the reason correctly explains the assertion. The assertion talks about lubricants reducing friction between surfaces, while the reason discusses the shape of rockets reducing air friction.

4. **Conclusion**: Since the reason does not explain how lubricants work to reduce friction, it is not a correct explanation of the assertion. Therefore, we conclude that both the assertion and the reason are true, but the reason is not the correct explanation for the assertion.

5. **Final Answer**: The correct option is that both the assertion and reason are true, but the reason is not the correct explanation of the assertion.