Which of the following functions is continuous but not differentiable at x = 1? x, x51 x, xs1 I. y=Vx-1 II. y= III. =1 2x, x>1 x>1 O A. I only O B. II only O c. I and Ill only O D. II and Ill only E. All of these functions are continuous but not differentiable at X = 1