A particular reaction is overall endothermic but is observed to proceed rapidly at room temperature. Which of the following best explains this observation?
a) The products are at a lower energy than the reactants, so the reaction is thermodynamically favored and therefore fast
b) Because the reaction has a large positive entropy change (ΔS>0), it is spontaneous and proceeds quickly despite being endothermic
c) The activation energy for the rate-determining step is low, allowing many molecules to reach the transition state
d) The reaction rate is independent of the activation energy and depends only on the overall enthalpy change