The graph of y=f(x) has an open circle at (2,3) and a filled dot at (2,5). On both sides of x=2, the curve approaches the open circle smoothly.
Which statement best describes f at x=2?
a) f is continuous at x=2 because x→2limf(x) exists
b) f is not continuous at x=2 because f(2) does not exist
c) f is not continuous at x=2 because f(2)=x→2limf(x)
d) f is continuous at x=2 because x→2−limf(x)=x→2+limf(x)