A twice-differentiable function h has first derivative h′(x)=x2e−x(x−3). Which of the following statements about the graph of h is true?
a) h has a local maximum at x=0 and a local minimum at x=3.
b) h has a local minimum at x=0 and a local maximum at x=3.
c) h has neither a local maximum nor a local minimum at x=0, and it has a local minimum at x=3.
d) h has local minima at both x=0 and x=3.