The locus of the mid-point of the chord of contact of tangents drawn from points lying on the straight line 4x - 5y = 20 to the circle $$x^2 + y^2 = 9$$ is

A

$$20(x^2 + y^2) - 36x + 45y = 0$$

B

$$20(x^2 + y^2) + 36x - 45y = 0$$

C

$$36(x^2 + y^2) - 20x + 45y = 0$$

D

$$36(x^2 + y^2) + 20x - 45y = 0$$