If an object in motion, experiences a net zero unbalanced force, the the body 1) will always remain at rest
2) cannot remain at rest
3) can be accelarated
4) moves with constant velocity

please choose the suitable option and give an explanation (not necessary) .

4) moves with constant velocity

Explanation:

If an object is in motion, three things can happen:

1. The object slows down in speed.

This means a net force is needed to be able to slow the object down in speed.

2. The object increases in speed.

This means a net force is needed to be able to increase the speed of the object.

3. The object remains in motion at the same speed.

No net zero unbalanced force is needed.

This is the given situation. So this is the right answer.