What does a measure of your cardiorespiratory endurance tell a fitness professional?
a. your aerobic fitness, or how efficiently your heart is working
b. your anaerobic fitness, or how well your leg and arm muscles work
c. how long you can sustain a weightlifting program
d. what type of exercises you’ve been doing

The correct option is A.
Cardio respiratory endurance refers to the measurement of the capability of the body to deliver oxygen and nutrients to tissues and to remove waste products over a specified period of time. Thus, it measures the ability of the lungs to take in oxygen and deliver it to the heart and the working muscles when one is undergoing physical activities. The value of one's cardio respiratory endurance shows how well one heart is working.

The correct answer is "grounded".