ἐρωτητέον
From LSJ
τῶν δ᾽ ὀρθουμένων σῴζει τὰ πολλὰ σώμαθ᾽ ἡ πειθαρχία → But of those who make it through, following orders is what saves most of their lives (Sophocles, Antigone 675f.)
English (LSJ)
verb. Adj. A one must ask, ἐρώτημα Arist.APo.77b7.
Greek (Liddell-Scott)
ἐρωτητέον: ῥημ. ἐπίθ. τοῦ ἐρωτῶ, δεῖ ἐρωτᾶν, Ἀριστ. Ἀναλυτ. Ὕστ. 1. 12, 2.