Answer:
The correct answer is inertia.
Explanation:
Inertia is called in physics the resistance that bodies oppose to modify their state of motion or stillness, either to alter their speed, their course or to stop; although the term also applies to the modifications of your physical state.
A body, thus, requires a force that overcomes inertia to alter its trajectory, which would otherwise adhere to the laws of uniform rectilinear motion, or to initiate a movement, otherwise it would remain at rest. This, of course, considering that there is no rest or rectilinear and uniform movement in the universe, except based on a reference (observation) system. That is why it is preferred to speak of "relative rest."
