Question

When no force acts on a body, it must be _______.

• A. Moving
• B. At rest
• C. In uniform motion
• D. Either B or C

Answer 1

The correct option is D Either B or C

According to Newton's first law, any object if at rest will remain at rest and if in motion will remain in motion until and unless an external unbalanced force acts upon it.

In option (a) the motion is not described, it may be a motion with acceleration which can only happen when force is applied.

Therefore, both (b) and (c) are correct hence, option $D$ is correct.