Consider the following utility functions.

G(x,y) = -1 / [ min(6x,2y)+1]

H(x,y) = min(6x,6y)

L(x,y) = min(6x,2y) - 10000000000

U(x,y) = min (3x, y)

W(x,y) = min (6x, y)

Z(x,y) = min (x,2y)

Which function or functions do not satisfy monotonicity?

a.H

b.None.

c.Z

d.W

e.L

f. G