Answer: B . resting heart rate
Step-by-step explanation:
The resting heart rate of an individual is a good measure of how fit the person is so is a very useful piece of information to have for an individual looking to improve cardiorespiratory endurance.
Even though a normal resting heart rate is to be between 60 and 100 beats per minute, a lower resting heart rate indicates that the person is fit. For instance, an athlete like Cristiano Ronaldo or Lebron James might have a resting heart rate of between 40 - 50 bpm.
This information will therefore let a person know if they need to improve their endurance as well as what targets they should set.