The statements in the following multiple choices deal with the concept of equilibrium. Choose the statement which is true. a) At equilibrium the speed of a reaction equals its rate constant. b) When products are less stable than reactants a reaction proceeds forward to reach equilibrium. c) As a reaction proceeds backwards toward equilibrium the reactant concentrations rise. d) As a reaction proceeds forward toward equilibrium the reverse rate constant rises. e) At equilibrium the rate constants of forward and reverse reactions are equal.