Answer:
C. But be careful. This question is poorly conceived. Anything could be the answer.
Step-by-step explanation:
A B and D are all specific to the disciple they are involved in.
That only lets you choose C. You could argue that a physicist or an electrical engineer would not be particularly interested in the death of some elm trees, and I think I would agree with you.
But what other choice to you have?
While the professor is tracking the fresh water fish, how is that benefiting mankind? What is he learning that is universally applicable. I wouldn't choose A.
B is an advance in technology. It might make the dairy farmer's life a whole lot easier, but I don't think it would have very effect on anyone else. Not B.
D: Again this benefits surgeons but again it is technology. I don't think it universally benefits all of humanity except those who are going to be operated on.
So I'll stick with C. People die. So do trees and all vegetation. I'd pick C, but I don't think there is a clear cut answer. Sometimes you get questions that you think the answer resides only in the head of the person writing the question. This is one of them.