Which of the following are true statements?

a. Changes in demand will cause a change in the equilibrium price and/or quantity, ceteris paribus.

b. Changes in supply will cause a change in the equilibrium price and/or quantity, ceteris paribus.

c. Supply and demand curves can shift simultaneously in response to changes in both supply and demand determinants.

d. When simultaneous shifts occur in both supply and demand curves, we will be able to determine one, but not both, of the variables.

e. All of these are true.