Yes. You can separate the sentence at “Nearly two years later...” by adding a period after CIA.
Answer:
I think A sounds the most descriptive.
C. If you feel like you have enough good information for your answer, then you will probably be right. Typically, it takes several sources but it will be worth finding to get good on an essay. Good luck!
Well, since Elaborate is a synonym for explain, I would guess that the student would just have to explain more about the topic.