(A) : A person can walk on a rough surface
(R) : Reaction of the force applied by the man on the surface keeps him moving

Options

A. Both (A) and (R) are true and (R) is the correct explanation of (A)
B. Both (A) and (R) are true and (R) is not the
C. (A) is true but ( R) is false
D. Both (A) and (R ) are false

Answer

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

**Assertion (A):** A person can walk on a rough surface.
**Reason (R):** The reaction of the force applied by the man on the surface keeps him moving.

### Step-by-Step Solution:

1. **Understanding the Assertion:**
- A person can walk on a rough surface because the surface provides the necessary frictional force. This friction is what allows the person to push against the ground and move forward.

**Hint:** Consider the role of friction in walking.

2. **Analyzing the Reason:**
- When a person walks, they apply a force on the ground in the backward direction. According to Newton's third law of motion, for every action, there is an equal and opposite reaction. Therefore, the ground exerts an equal and opposite force (reaction) on the person in the forward direction.

**Hint:** Recall Newton's third law of motion and how it applies to walking.

3. **Components of Forces:**
- The force exerted by the person has two components:
- A vertical component that acts downward (equal to the weight of the person).
- A horizontal component that acts backward due to the push against the surface.
- The ground provides a reaction force that has two components as well:
- A normal force that acts upward to balance the weight of the person.
- A horizontal component that acts forward, which is the frictional force that propels the person forward.

**Hint:** Think about how forces balance each other and how they contribute to motion.

4. **Conclusion:**
- Both the assertion and the reason are true. The reason correctly explains why the assertion is true: the reaction force from the surface allows the person to move forward, which is essential for walking.

**Hint:** Make sure to connect the assertion and reason logically.

### Final Answer:
Both assertion (A) and reason (R) are true, and the reason (R) is the correct explanation of the assertion (A).