The amount of space required by a particular firm is given below, where x and y are, respectively, the number of units of labor and capital utilized. ( H = 3x² + 5xy + 2y² ). If the firm wants to minimize its space requirements, which combination of labor and capital should it utilize?
a) (x = 1, y = 1)
b) (x = 2, y = 3)
c) (x = 4, y = 2)
d) (x = 3, y = 4)