show the market for pianos in 2008. Between 2008 and 2009, the equilibrium quantity of pianos remained constant, but the equilibrium price of pianos increased. From this, you can conclude that between 2008 and 2009, the supply of pianos (A)was unchanged (B) increased or (C) decrease and the demand for for pianos (A) unchanged (B) increased (C) decreased. Please choose and answer for each