umm, MCQ 2.A? Isn't it? B) doesn't work cause, for example, if you sub it in, (-4-3i)^2 = 16-9+24i = 7+24i not 7-24i.
Or if you prefer the longer method, of equating real and imaginary components/completing the square, x^2-y^2 = 7, 2ixy = -24, xy = -12, by inspection, x=4, y=-3 or x=-4, y=3...