The derivative of a differentiable function f satisfies f′(2.9)=−1.2, f′(3)=0, and f′(3.1)=0.8. It is also known that f′′(3)=0. Which of the following conclusions about f at x=3 is most accurate?
a) The graph of f has a point of inflection but neither a maximum nor a minimum at x=3.
b) No determination about relative extrema can be made from the given information.
c) The graph of f has a relative minimum at x=3.
d) The graph of f has a relative maximum at x=3.