Answer:
1. -1
Explanation:
Since we know that i is an imaginary number. We also know that
and
.
Let us see i raised to different powers.
We can see that when we raise i to 3rd power and 7th power we got -i and when we raised i to 5th and 9th power we got i.
Therefore, if we raise i to an odd power, it can not simplify to be -1 and 1st option is the correct choice.