A function f is examined at x=c using the following statements.
I. f(c) exists.
II. x→climf(x) exists.
III. x→climf(x)=f(c).
Which of the above statements must all be true to guarantee that f is continuous at x=c?
a) I and II only
b) II and III only
c) I, II, and III
d) I only