The best answer to the question above would be letter c. The mode of exercise refers to the <em>type </em>of exercise performed. These are exercises that fall under categories such as strength, flexibility, agility training and all those categories of exercises for the sake of training for function.
You get tired when you run because our leg muscles don't get enough oxygen anymore.
I fins that in helps to remember and implement suffixes, especially in regard to health care. The suffix of breast is -mastia. The suffix of without is a-. So the answer would be Amastia.