Let h be twice differentiable with h′′(x)>0 for x<5 and h′′(x)<0 for x>5. The tangent line at x=5 is used to approximate h(4.8) and h(5.4). Which option correctly gives the sign of the error (approximation minus actual value) at each point?
a) Positive at x=4.8 and positive at x=5.4
b) Positive at x=4.8 and negative at x=5.4
c) Negative at x=4.8 and positive at x=5.4
d) Negative at x=4.8 and negative at x=5.4