If No FD selected on then as others have mentioned you end up with CWS in both pitch and roll.
Indeed, and that is THE question: What are the muscles of CWS.
But to answer this at last, one need to decipher the original wording at first. In order to do so, one needs to know the regimes of AP system on 737, their limitations (AP with no FD trips to / engages only in CWS) and functions. Only then you can asses the outcome on stability as the question suggests.
For a student, it is quite uneasy.
Edited for typos