Final answer:
The 'normal operating range of skeletal muscle' is not accurately represented by any of the given options as skeletal muscles can operate within a range that extends beyond these choices, typically up to around 120 degrees for many joints during various activities. Skeletal muscle function and movement ranges greatly depend on the joint and the specific activity being performed.
Step-by-step explanation:
The question 'What is the normal operating range of skeletal muscle?' refers to the typical range of motion that skeletal muscles can safely and effectively operate within. When considering the angles of joint movement facilitated by skeletal muscles during contraction, the options provided do not necessarily correspond to a 'normal operating range' because this range can vary greatly depending on the specific joint and movement in question. However, for many joints, a range of motion within 0 to around 120 degrees could be considered normal for various activities. Thus, none of the given options accurately represents the normal operating range of skeletal muscle. It’s also important to note that the context in which the range is applied could be during activities such as walking, lifting, or other daily functions.
The normal range for body temperature, as another example of a physiological set point with a normal range, would be about 36.5 to 37.5 °C (97.7 to 99.5 °F).