As mentioned, the Asker is the only one that can choose a Best Answer. What may have happened is that the Best Answer was reported and removed as a violation after the person chose it and the notification went out to you. This does happen; being chosen as BA doesn't grant immunity to an answer, and many BAs are still violations.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.