Christians believe that to avoid Hell you must accept Jesus Christ as your Lord and Savior. Anyone who does not accept Christ as their Lord and Savior goes to hell according to this doctrine.
I think we can all agree that Adolf Hitler was a truly evil person and if anybody deserved to burn in hell forever it would be him. (Although it's interesting to note that in his autobiography he claimed to be a Christian but never mind.) But what about Anne Frank? She was a Jew so she never accepted Jesus Christ as her Lord and Savior.
So if you want to tie conservative Christians in knots, ask them if Anne Frank is in hell with Adolf Hitler. And yes, this is a fair question.