For each of the following pairs of materials, determine which would have the higher electrical conductivity and then cite the reason for your choice. $(2$ points$)$

a$.$ CdS at $293K($room temp$)$ vs$.$ CdS at $500K$

b$.$ Al at $293K($room temp$)$ vs$.$ Al at $500K$

c$.$ Si doped with donors vs$.$ Si doped with ${10}^{24}{m}^{-3}$ donors, both at room temperature

d$.$ Cu with $5\%$ CW vs$.$ Cu with $10\%$ CW

e$.$ A $60wt\%Sn-40wt\%Pb$ solder vs$.$ a $50wt\%Sn-50wt\%Pb$ solder, both at room temperature