Which of the following represents the zeros of f(x) = x^3 − 4x^2 − 5x + 20?


a. 4, −square root of 5, −square root of 5


b. −4, square root of 5 , square root of 5


c. 4, square root of 5, −square root of 5


d. −4, −square root of 5, −square root of 5