Which of the following has a higher osmolarity concentration compared to the others listed?

a) 1 mole of W with a dissociation factor of 0.5
b) 1 mole of substance Z with a dissociation factor of 1.7
c) 2 moles of substance Y with a dissociation factor of 0.8
d) 3 moles of V with a dissociation factor of 0.2