Are Markets Always in Equilibrium

Multiple Choice

Are markets always in equilibrium?

A) Yes they are always in equilibrium because very few things tend to alter supply and demand.
B) No, but if there is no outside interference, they tend to move toward equilibrium.
C) No they are not always in equilibrium because they never "settle down" to a stable price and quantity.
D) Yes, they are always at the equilibrium point, or very close to it.