While unlikely, if Jesus actually says Beelzebub, the priests have every right to take him to the temple wall and hurl him into the valley below. The possibility of the third answer, claiming authority from God, gives Caiaphas an anticipation so strong the muscles on his belly tremble. If they hear this answer, they will stone him as a heretic before any crowds can form to protest and protect him. Jesus stares back. He knows the High Priest's mind.
Silence makes tension.
He begins so casually, listeners might guess this is simply another matter of teaching to be discussed. Answer me, and I will tell you by what authority I am doing these things. Abruptly, Jesus raises his voice. His face, gentle and amused, has stiffened to match the sudden anger in his voice. It is as if an invisible mantle of power has been placed upon him, as if Jesus is now judge and the delegation on trial.