Final answer:
The correct answer is B. RPE (Rate of Perceived Exertion), which is a subjective measure used to assess exercise intensity based on an individual's own feelings of effort.
Step-by-step explanation:
The correct answer is B. RPE (Rate of Perceived Exertion). The Rate of Perceived Exertion is a subjective measure that individuals can use to assess the intensity of their physical activity. This scale factors in the personal feelings related to one's effort during exercise. Unlike quantitative measures such as resting heart rate, BMI, or VO2max, RPE relies on an individual's own perception of effort, which can be influenced by various factors including but not limited to physical condition, emotional state, and overall fatigue. The use of RPE is valuable because it provides insight into how hard one feels they are working, regardless of other measurable physiological responses.