The one-sided limits of the derivative of a continuous function f at x=2 are
x→2−limf′(x)=−3,x→2+limf′(x)=5.
Which of the following is most consistent with the behavior of f at x=2?
a) f has a vertical tangent line at x=2.
b) f has a sharp corner at x=2.
c) f has a removable discontinuity at x=2.
d) f has a local extremum at x=2.