The correct response regarding the impact of lowering the draft age during WWII and the Vietnam War is:
It led to demands to lower the voting age to 18.
Lowering the draft age created a situation where young men could be drafted to fight in wars without having the right to vote. This inconsistency fueled movements advocating for the voting age to be lowered to 18, reflecting the idea that if individuals were old enough to be conscripted into military service, they should also have the right to vote on the issues that affected their lives.