How Does the American Physical Therapy Association (APTA)define Muscle Strength

How does the American Physical Therapy Association (APTA) define muscle strength?

A) The muscle force exerted by a muscle or group of muscles to overcome resistance under a specific set of circumstances
B) The capacity of a muscle or group of muscles to generate force
C) The work produced per unit of time
D) The ability to sustain force repeatedly or to generate force over a period of time