Two aqueous solutions are both at room temperature and are then mixed in a coffee cup calorimeter. The reaction causes the temperature of the resulting solution to fall below room temperature. Which of the following statements is TRUE?

a. The products have a lower potential energy than the reactants.
b. Energy is leaving the system during reaction.
c. This type of experiment will provide data to calculate ?Erxn.
d. The mixing is endothermic.
e. None of the above statements are true.