When one body rolls over the surface of another body, the resistance to its motion is called :

Options

A. Rolling friction
B. Sliding friction
C. Fluid friction
D. Static friction

Explanation

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks about the type of resistance encountered when one body rolls over the surface of another body.

2. **Identifying Types of Friction**: There are different types of friction, including:
- **Static Friction**: The friction that prevents motion when an object is at rest.
- **Sliding Friction**: The friction that occurs when an object slides over a surface.
- **Rolling Friction**: The friction that occurs when an object rolls over a surface.

3. **Analyzing the Scenario**: In this case, since we are dealing with a body that is rolling, we need to focus on the type of friction that is relevant to rolling motion.

4. **Defining Rolling Friction**: Rolling friction is the resistance that occurs when an object rolls over a surface. It is typically less than sliding friction, which is why rolling objects (like wheels) are more efficient for movement.

5. **Conclusion**: Therefore, when one body rolls over the surface of another body, the resistance to its motion is called **rolling friction**.

**Final Answer**: Rolling friction.

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