The temperature inside a vehicle is modeled by the function f, where f(t) is measured in degrees Fahrenheit and t is measured in minutes. The first derivative off is given by f' (t) = t² - 3t + cost. At what times t, for 0 < t < 4, does the temperature attain a local minimum?

A) 0.354 only
B) 1.962
C) 3.299 only
D) 0.354 and 3.299