Which represents a quadratic function?


A; f(x) = −8x^3 − 16x^2 − 4x

B; f(x) = 3/4 x^2 + 2x − 5

C; f(x) = 4/x^2 - 2x +1

D; f(x) = 0x^2 − 9x + 7
WILL MARK BRAINLIEST!