My question would be "WHAT WOULD THE OTHER GUARD SAY IF I WILL ASK HIM WHERE THIS DOOR LEADS?"
Let's assume that A door leads to freedom.
If the guard in A door is an honestant then he would answer "THIS DOOR LEADS TO THE SCAFFOLD"
If the guard in A door is a swindlecant then he would also asnwer "THIS DOOR LEADS TO THE SCAFFOLD"
But if A door leads to scaffold then the honestant would answer "THIS DOOR LEADS TO FREEDOM" and if the guard is swindlecant he would answer "THIS DOOR LEADS TO FREEDOM"
WHAT WOULD THE OTHER GUARD SAY IF I WILL ASK HIM WHERE THIS DOOR LEADS?