If one root of the quadratic equation \( 4x^2 - 8kx - 9 = 0 \) is negative to the other, then the resulting equation is:

A \( 4x^2 - 9 = 0 \)

B \( 4x^2 - 8x - 9 = 0 \)

C \( 4x^2 + 8x - 9 = 0 \)