According to Newton's First Law of Motion, what happens to a body at rest?

Newton's First Law of Motion states that an object at rest will remain at rest unless acted upon by a net external force. This means that if no force is applied to the object, it will not change its state of motion. Essentially, it highlights the concept of inertia, which is the tendency of an object to resist changes to its state of motion. Therefore, if an object is at rest, it will continue to be at rest until something else—such as a push or pull—intervenes to change that state.

In contrast, the other options suggest scenarios that do not align with this principle of inertia. For example, stating that an object will accelerate indefinitely implies a constant force acting on it, which goes against the law. Suggesting that it will begin to move at random lacks any basis in physics, as there's no mechanism for random movement without an external force. Furthermore, saying it will slowly decrease in speed implies a change in motion without a force acting upon it, which also contradicts the First Law. Hence, the correct choice emphasizes the passive state of an object at rest maintained by the absence of external forces.