If two points are in a common reference frame, then a They are not in motion relative to each other. They are not accelerating relative to each other. They are in the same gravitational field. They must be the same point. Solution the motion has to be described with respect to a reference frame Now in the given scenario if both the particles are in the same frame of reference, it may be possible that both of them are moving with respect to the frame of reference. With the given options, it is most likely that they are not moving relative to each other. (a) any information about the nature of reference frame could have been more useful. .