If We Observe a Decrease in the Equilibrium Quantity of Good

Multiple Choice

If we observe a decrease in the equilibrium quantity of good A, we know that

A) either the demand for A has increased or the supply of A has increased or both.
B) either the demand for A has decreased or the supply of A has decreased or both.
C) either the demand for A has increased or the supply of A has decreased or both.
D) either the demand for A has decreased or the supply of A has increased or both.
E) the price of A has fallen.