The answer is:
Client, environment, health, and nursing
Some of these can easily be eliminated by knowing that both nitrogen 14 and nitrogen 15 are isotopes ( same element, with the same amount of protons, but with different numbers of neutrons) of nitrogen. So if the only difference between nitrogen 14, 15 , and regular nitrogen is the amount of neutrons...how many protons and electrons should both nitrogen 14 and 15 have? After thinking, you should be able to eliminate A, B,and C.
Because he is assigned to bring Percy to camp, and if he doesn't he will not get his searchers license. P.S. I love this series!!!
