Simplify the number using the imaginary unit i:
(square root) -28
options:
A2(square root) -7
B-2(square root) -7
Ci(square root) 28
D2i(square root) 28
(square root) -28
options:
A2(square root) -7
B-2(square root) -7
Ci(square root) 28
D2i(square root) 28