(a) Find all values of x where the function is discontinuous, and (b) graph the given function. 7x +7 if x 0 (a) Find all values of x where the function is discontinuous. O A. The function f is discontinuous at x = 0 and x = 7. O B. The function f is discontinuous at x = 7. O C. The function f is continuous for all values of x O D. The function f is discontinuous at x = 0