The correct option is (c).
Explanation
To describe the motion or location of an object, a frame of reference is required. This frame consists of a coordinate system with a reference point called the origin. All measurements of position are made relative to this point.
Statement 1 is Incorrect:
The origin is a geometric reference point, not necessarily a physical object. Furthermore, it does not need to be stationary. Since motion is relative, an origin can be attached to a moving body (such as a moving train or the Earth). There is no concept of absolute rest in physics; an origin is only stationary with respect to its own frame of reference.
Statement 2 is Correct:
The choice of origin is arbitrary and depends on the observer's convenience. For instance, in a road trip, the starting point, the destination, or a milestone on the highway can all serve as the origin. Changing the origin changes the coordinates of position but does not alter the physical event of motion itself.
Statement 3 is Correct:
Position is defined as the location of an object relative to the chosen origin. It is specified using coordinates (e.g., x, y, z) or a position vector, which indicates both the distance and direction from the origin to the object.
Key Takeaway:
Motion is relative. The origin is an arbitrary reference point used to define position coordinates, and it can be chosen freely to simplify the analysis of a problem.