If We Observe a Fall in the Equilibrium Price of Product

Multiple Choice

If we observe a fall in the equilibrium price of product A, we know that either the demand for A has

A) increased or the supply of A decreased or both.
B) increased or the supply of A increased or both.
C) decreased or the supply of A increased or both.
D) decreased or the supply of A decreased or both.
E) none of the above.