The function h is continuous on [0,6] and differentiable on (0,6). It is known that
• h′(x)>0 for 0<x<2,
• h′(x)<0 for 2<x<4,
• h′(x)>0 for 4<x<6,
and h(0)=1, h(2)=5, h(4)=2, h(6)=3.
Which statement correctly identifies the absolute minimum of h on [0,6]?
a) It occurs at x=4 because h′(x) changes from negative to positive there.
b) It occurs at x=6 because h is increasing on (4,6).
c) It occurs at x=0 because h(0) is less than the function values at all other candidates.
d) It occurs at x=4 because h(4) is less than the function values at x=2 and x=6.