The answer is A. this is because he is giving his opinion that may be different from others' and it is rude to say that someone's idea is stupid.
Exercising allows the body to keep a healthy heart rate, healthy blood sugar levels, and many more important things for someone’s body. Exercising is important not only physically, but it is also important mentally. Exercising is proven to alleviate stress and release serotonin, as well as help people feel good about themselves after. This is especially significant for children, because exercising will help them physically in the long-term and will also help them mentally with having some way to release stress and from healthy coping mechanisms.
She should try to get a day off so she can let her muscles relax and have time to rebuild new muscle. Remember that muscle grows slowly so within 24 hours muscle starts to grow thus she should rest for at least 1 or 2 days so she doesn't exhaust her body.
I believe skeletal muscle fibers are dependent on oxygen and steady blood flow. Hope this helps.
