Rule reminder
'Quand'anche' (sometimes written 'quand anche') is a formal literary connective meaning 'even if' used to introduce a hypothetical concessive clause. It is always followed by the condizionale (present or past) in the subordinate clause, and the main clause typically also uses the conditional. Example: 'Quand'anche mi supplicasse, non cambierei la mia decisione.' It is more emphatic and literary than 'anche se' + congiuntivo.
'Quand'anche _____ tutto il possibile, non basterei a convincerli.' Choose the correct form.