Mark M. answered 11/15/20
Retired math prof. Calc 1, 2 and AP Calculus tutoring experience.
The answer is choice "A".
The limit of a function at a certain point can exist, but the function itself may be undefined at that point.
For example, if f(x) = (x2 - 1) / (x - 1), then limx→1 [(x2 - 1) / (x - 1)] = 2, but f(1) is undefined as there is a "hole" in the graph at the point (1,2).