Die Gretchenfrage

In German "Gretchenfrage" means roughly "crucial question".

Examples:

Die Gretchenfrage, ob die Reformen geholfen haben, wurde nicht gestellt.
(The crucial question of whether the reforms helped was not asked.)

Die Gretchenfrage, ob er das mit Absicht getan hat, wurde nie geklärt.
(The crucial question of whether he did it on purpose was never resolved.)

"Frage" means question, Gretchen is a female given name of German origin. It is the diminutive form of Grete or Greta. (The diminutive form is formed with the suffix -chen)

Gretchen/Greta is not a common name in present day Germany. Gretchen is a major character in Faust, a tragic play by Johann Wolfgang von Goethe.