All of the following pairs of structures are homologous [huh-MOL-uh-guhs], EXCEPT:

W) The wing of a bat and the wing of a bird

X) The leg of a human and the leg of a centipede

Y) The scales on a bird's legs and the scales on a lizard

Z) The shell of a clam and the shell of a snail
X) THE LEG OF A HUMAN AND THE LEG OF A CENTIPEDE