Producer surplus is calculated: to. adding the minimum price plus the equilibrium price, then multiplying it by the equilibrium quantity and the result is divided by two. b. adding maximum price plus equilibrium price, then multiplying by the equilibrium quantity and the result is divided by two. c. subtracting equilibrium price minus minimum price, then multiplying by the equilibrium quantity and the result is divided by two. d. subtracting equilibrium price minus maximum price, then multiplying by the equilibrium quantity and the result is divided by two.