For the presented problem, let’s say for the example (x^2-a^2)^2, the roots are only a and -a, but it may be possible that they’d count each root twice but can be prevented if they’re looking at the graph. You can actually make out two real zeroes and two imaginary ones from the example. (x+1)(x-1)(x+i)(x-i) is (x^2-1)(x^2+1)= x^4-1. I am hoping that this answer has satisfied your query about this specific question.