Answer:
A. 0 m/s
Explanation:
The rest frame of an object is defined as the reference frame that is moving together with the object, so at the same speed of the object.
In other words, the rest frame of an object is defined as the reference frame in which the object is at rest, which means that is the reference frame in which the object has speed equal to zero (0 m/s).
Therefore, the correct answer is
A. 0 m/s
