Many fitness programs include weight training, which A. can be used in place of aerobic exercise, when done regularly. B. helps
to increase cardiorespiratory capacity and endurance. C. helps to increase muscular strength and endurance. D. is a form of aerobic exercise involving the muscles.
The answer would be C) because weight lifting is used to increase your muscular strength, and that's why you try and add more weight during sessions, so it's not too easy for you and you can build a higher endurance.