Assertion: Frictional force is the component of contact force parallel to the surface.
Reason: Friction force always opposes the motion of a body.

Options

A. If both assertion `&` Reason are True `&` the Reason is a corrrect explanation of the Asserion.
B. If both Assertion `&` Reason are True but Reason is not correct explanation of the Assertion.
C. If Assertion is Trie but the Reason is False.
D. If both Assertion `&` Reason are false

Explanation

To solve the question, we need to analyze the assertion and the reason provided.

### Step 1: Analyze the Assertion
The assertion states that "Frictional force is the component of contact force parallel to the surface."

- **Explanation**: When two surfaces are in contact, the forces acting between them can be divided into two components: one that is perpendicular to the surface (normal force) and one that is parallel to the surface (frictional force). The frictional force arises due to the interactions at the microscopic level between the surfaces in contact and acts parallel to the surface.

### Step 2: Analyze the Reason
The reason states that "Friction force always opposes the motion of a body."

- **Explanation**: While it is generally true that friction opposes the relative motion between surfaces, there are scenarios where friction can act in the direction of motion. For example, when two blocks are in contact and one is being pulled, the frictional force can act in the direction of the motion of the block on top, helping it to move. Thus, this statement is not universally true.

### Conclusion
- **Assertion**: True (Frictional force is indeed the component of contact force parallel to the surface).
- **Reason**: False (Friction does not always oppose the motion; it can also assist in motion under certain conditions).

### Final Answer
The assertion is true, but the reason is false.

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