The answer is A,.................
Answer:
cleaning under the fingernails
Explanation:
Participating in extreme sports can help your cardiovascular system work properly and better because extreme sports usually are very taxing in terms of being an aerobic sport which also puts a lot of burden on the aerobic system. Another benefit would be not so health-related but more personal; doing extreme sports and being close to death - which can hppen - makes one more appreciative and aware of life and death.
