In this reaction
[the figure shows a scheme of a chemical reaction. the reactants are two molecules, one of which consists of a and b, the other - of c and d. the products are two molecules, one of which consists of a and c, the other - of b and d. the potential energy of molecules ab and cd is higher than the potential energy of molecules ac and bd.]
a. the products have been rearranged to form reactants
b. ac is a reactant
c. cd is a product
d. the products have less potential energy than the reactants
e. entropy has decreased