(a) S_inelastic and D_inelastic show little price sensitivity. With price controls, relatively few buyers and sellers who would have traded in the free market are kept out of the market, and the transfer is much larger than the deadweight loss created.
(b) In a market with a more elastic supply and demand curve, S_elastic and D_elastic, a relatively large group of buyers and sellers who would have traded in the free market are kept out of the market, and the deadweight loss created by the price control is much larger than the transfer.