Which of the following conditions is sufficient to conclude that f has a removable discontinuity at x=c?
a) The left-hand and right-hand limits at x=c both exist but are not equal, regardless of f(c).
b) x→climf(x) does not exist, but f(c) is defined and finite.
c) x→climf(x) exists and is finite, but f(c) is either undefined or not equal to that limit.
d) x→climf(x)=f(c), yet f′(c) does not exist.