The center of mass is best described as:

• A. The point at which the body's weight is equally distributed.
• B. The location where the body's weight is concentrated.
• C. The point from which all external forces are measured.
• D. The average location of all joints.

Answer: (A)

Center of mass is the balance point of the body—the single location where the body's mass can be considered to be concentrated. Under gravity, the weight acts through this point, so if you support the body at the center of mass there’s no net torque from gravity and the body remains balanced. This point isn’t about weight being dispersed evenly across the body; it’s about the overall mass distribution acting as a single resultant force through one spot. As you move limbs or change posture, the center of mass shifts, which is why balance changes with different positions. In standing humans it’s typically near the lower abdomen/pelvis region, and it moves with posture and movement.