Final answer:
a. Muscle type. The work function of a muscle is usually calculated by calculating the work done by the muscle, which is the product of force and displacement.
Step-by-step explanation:
The work function of a muscle is usually calculated by calculating the work done by the muscle. Work is defined as the product of force and displacement. In the case of a muscle, the force exerted by the muscle and the distance over which the force is applied can be used to calculate the work done.
For example, if a muscle exerts a force of 100 newtons and the muscle contracts over a distance of 2 meters, the work done by the muscle would be 200 joules (100 newtons * 2 meters).
Therefore, the correct option for calculating the work function of a muscle is b. Calculating force x distance.