Answer:
An object’s position changes if there is a change in reference point.
Thus Option A is the right answer
Step-by-step explanation:
When a place and object is used to compare whether an object is in motion or not, this place or object is considered as reference point. We call an object is moving when the distance between that object and another object changes.
In order to find out a movement of an object we generally consider the reference point as still. We say an object is in movement when it changes position in relation with the reference point.