Answer:
Step-by-step explanation:
Discussion
i has to appear somewhere. That lets D and B out. They are both wrong.
C has only one i. It can't be right either. You need 2 i-s which will multiply to +1 when squared. That leaves you with a.
The way a is written, it can't be the answer either. For one thing, that 2 makes the answer question at best.
I would say there is no correct answer. Could you check the question? Also it would be a good idea to ask your instructor how this works, in case I'm wrong.
