Let h(x)=x3−6x2+11x−6, which has simple zeros at x=1,2,3. A student wants to approximate the zero at x=2 using interval halving on an interval of length 0.8. Which interval choice both contains exactly one zero and is such that h is strictly monotonic throughout the interval?
a) [1.8,2.6]
b) [1.5,2.3]
c) [2.2,3.0]
d) [1.5,2.2]