When governments impose price ceilings on apartments below the equilibrium rent, what happens in the long run? 

A. The quantity of available rental housing units falls, but the quality of those units is unaffected 

B. The quality of rental housing units falls, but the quantity remains unaffected 

C. Both the quantity of available rental units and their quality decline 

D. Landlords earn lower profits from renting housing units, but the rent charged has no effect on either