Sasha owes $600 to Yale, who asks Sasha to sign an instrument for the debt. If included

Question:

Sasha owes $600 to Yale, who asks Sasha to sign an instrument for the debt. If included on that instrument, which of the following would prevent its negotiability—“I.O.U. $600,” “I promise to pay $600,” or an instruction to Sash’s bank stating, “I wish you would pay $600 to Yale”?