Which of the Following Demand Functions Is Not Homogenous of Degree

Multiple Choice

Which of the following demand functions is not homogenous of degree zero in p_x ,p_y ,and I?

A) x = I / (p_x,+ p_y ) .
B) $x = I ^ { .5 } p _ { x } ^ { - 03 } p _ { y } ^ { - 0.2 }$ .
C) $x = I p _ { y } / p _ { x } ^ { 2 }$ .
D) $x = I p _ { y } / p _ { x }$ .