The answer should be C.
"Increased Exercise."
In a professional environment, incorrect language could affect your profession.
The word abuse has a much stronger connotation than "bullying" which is usually associated with teasing. The former, however, is typically associated with emotional and/or physical harm on the body. If someone is being "bullied" and it involves harm on the body, then it could definitely go hand-in-hand with abuse.
What is VO2max?
Answer: First you have to understand that it stands for maximal oxygen uptake and is the amount of oxygen that your body is capable of using in one minute. If you are an athlete it is measure in order to tell you your capacity and your potential endurance. Therefore the answer is B) the highest level of oxygen consumption that can be sustained during exercise.
I hope it helps, Regards.