Newton's third law :

Options

A. defines the force qualitatively
B. defines the force quantitatively
C. explains the way a force acts on a body
D. gives the direction of force.

Explanation

To answer the question regarding Newton's third law, we will analyze the options provided and determine which one correctly relates to the law.

### Step-by-Step Solution:

1. **Understanding Newton's Third Law**:
- Newton's third law states that for every action, there is an equal and opposite reaction. This means that if one body exerts a force on another body, the second body exerts a force of equal magnitude but in the opposite direction on the first body.

2. **Analyzing the Options**:
- **Option 1**: Define the force qualitatively.
- This option is incorrect because defining force qualitatively relates more to Newton's first law, which describes the concept of force in terms of motion and rest.

- **Option 2**: Define the force quantitatively.
- This option is also incorrect as it pertains to Newton's second law, which quantitatively defines force as the product of mass and acceleration (F = ma).

- **Option 3**: Explain the way a force acts on a body.
- This option is correct because it aligns with Newton's third law. It explains how forces interact between two bodies, emphasizing that when one body exerts a force on another, the second body exerts an equal and opposite force back on the first body.

- **Option 4**: Give the direction of force.
- This option is partially correct but does not fully encapsulate the essence of Newton's third law, which is more about the interaction and the relationship between the forces rather than just their direction.

3. **Conclusion**:
- The correct answer is **Option 3**: Explain the way a force acts on a body, as it directly relates to the principle of action and reaction described by Newton's third law.