______________ is the ability of the muscle to exert force during an activity.FlexibilityMuscular strengthMuscular enduranceCardio-respiratory endurance

The correct answer to the question is Muscular strength.

Muscular strength refers specifically to the maximum amount of force that a muscle or group of muscles can exert during a single effort. This concept is crucial in various physical activities where the exertion of force is required, such as weightlifting, sprinting, and resistance training. It is distinct from muscular endurance, which is the ability of a muscle to sustain repeated contractions over time or to continue exerting force against a fixed resistance.

While flexibility pertains to the range of motion of muscles and joints, and cardio-respiratory endurance relates to the body's ability to supply fuel during sustained physical activity, muscular strength focuses directly on the force exerted at any given time. Therefore, when considering the ability of a muscle to exert force, muscular strength is the appropriate term.