Endurance is the answer i think you're looking for.
Try different methods of trying to get them to respond it would only make sense right??
Answer: A.
increase the size of the muscle cells and the amount of blood that is delivered to the muscle
Explanation:
Increasing the size of the muscle cells and the amount of blood that is delivered to the muscle is important when it comes to muscular endurance.
The greater muscular endurance is the higher number of exercises that are including muscle effort against a force for a particular period of time.
High muscle endurance is helpful to the human body and immunity.
The questions on those medical history forms contain some very important information.
hope this help!