Which of the following are examples of perfect substitute production functions? Choose one or more: D A f(X1, X2) = X1X2 Q B. f(X1, X2) = XX,450 D C. f(x1, X2) = min[1.5x1, X2] D D. f(x1, x2) = 1.5x1 + 4.50x2 D E. f(X1, x2) = min[1.5x1, 4.50x2] B F. f(x1, X2) = 1.5x1 + X2 D G. f(x1, x2) = min[x1, x2] D H. f (X1, X2) = x1 5 x2 0 1. f(x1, x2) = min[x1, 4.50x2] a J. f(x1, x2) = x1 5x2 x4.50 D K. f(X1. x2) = x1 + 4.50x2 O L f(X1, X2) = X1+ X2