Overload refers to: A. Performing a weight-lifting exercise with the resistance (load) held overhead B. Using a demand (load) above the normal demand faced by a muscle C. The principle that strength will be best developed when the resistance (load) exceeds the individual's physical abilities (e.g., 8 reps of the 5-RM) D. The principle that a resistance (load) must be presented repeatedly in order to elicit any adaptations E. All of the answers are correct

E. All of the answers are correct

Explanation:

Overload principle in fitness training is associated with a gradual development of an athlete's abilities by progressively increasing the athlete's load and training.

In order to do this, the athlete's limit must be surpassed albeit gradually at first then picked up later over time.

In particle kinematics, we measure the acceleration of the particle. For this, an observer is taken as a reference point. Generally we consider the observer as in origin of a co-ordinate system. The place where observer is placed is known as frame of reference. 
Newton's laws only work in the inertial frame of reference. Inertial frame is a frame of reference whose acceleration is zero. But, if you are observing the motion of an object from non-inertial frame, you need to add and extra force on the system under observation which is known as pseudo force.