Let \(A, B\) be two distinct points on the parabola \(y^{2}=4 x\). If the axis of the parabola touches a circle of radius \(r\) having \(A B\) as diameter, the slope of the line \(A B\) is
(A) \(-\frac{1}{r}\)
(B) \(\frac{1}{r}\)
(C) \(\frac{2}{r}\)
(D) \(-\frac{2}{r}\)
Ans(C,D)
