Answer:
D) 1
Step-by-step explanation:
When you start raising i to certain powers, you begin to notice a pattern.

This cycle repeats forever. Since 84 is a multiple of 4, i^84 must be 1. Hope this helps!
A is inbetween 2 and 4
B is inbetween 3 and 4
C is inbetween 4 and 5
D is inbetween 5 and 6
So the correct answer would be A B and C
I am not completely sure if tis is correct. I just took 16 and multiply them for the answer B and C. hope this can help you.