I actually got D for part 5. Say all the resistors have a resistance R, since they're identical. In the first circuit, R_T=R+R=2R. So the total current through the resistors is I_1=12/(2R)=6/R. So the current flowing through both resistors is 6/R. In the second circuit, 1/(R_T)=1/R + 1/R=2/R so...