While walking on the ground we apply force on____

Options

A. shoes
B. ground
C. gravitational
D. friction

Explanation

To solve the question "While walking on the ground we apply force on____", we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Action**: When we walk, we push our feet backward against the ground. This is an action that involves applying force.

2. **Identifying the Reaction**: According to Newton's Third Law of Motion, for every action, there is an equal and opposite reaction. Therefore, when we push against the ground, the ground pushes back with an equal force.

3. **Recognizing the Surface**: The surface we are walking on is the ground. The force we apply is directed towards the ground.

4. **Conclusion**: Since we are applying force on the ground while walking, the correct answer to the question is "ground".

### Final Answer:
While walking on the ground, we apply force on **the ground**.

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