reference frame definitely changes when also changes. speed velocity position direction

Brief Explanations:

A reference - frame is a coordinate system used to describe the position and motion of objects. When the position of an object changes, the reference frame relative to which its position is measured also changes. Speed, velocity, and direction are properties related to the motion of an object within a reference - frame, but a change in position directly implies a change in the reference frame used to measure that position.

Answer:

position