If we do not asses our environment, our risk of sickness and disease increases. Any kind of chemical or radiological substances in the air are exposures that can affect our health. Meaning that the air we breathe, foods we eat, the water we drink from, and the products we use can sicken us if they aren't properly cleaned or pure.
Answer: If your cancer is particularly sensitive to radiation therapy or chemotherapy, you may receive one of those therapies as your primary treatment. Adjuvant treatment.
Answer C is a good example for that because when starting a school club you mainly will be focusing on that and most likely won't have time to drink or hang out with drinkers.