A three-times differentiable function r satisfies r′′(x)=x−2 for all real x and r′′′(x)>0. Let T(x) be the tangent line to r at x=2. Which statement best describes whether T(x) overestimates or underestimates r(x) for values of x sufficiently close to 2?
a) T(x) underestimates r(x) on both sides of x=2.
b) T(x) overestimates r(x) for x<2 and underestimates r(x) for x>2.
c) T(x) underestimates r(x) for x<2 and overestimates r(x) for x>2.
d) T(x) overestimates r(x) on both sides of x=2.