Option No. 1: Matt Ryan looks to join a rebuilding team as a spot starter and a mentor to a young QB
Matt Ryan could choose to follow what Andy Dalton is doing in Carolina by signing with a team who has a high-draft pick that is bound to select a quarterback.
This is a logical option for Ryan if he is looking to continue his NFL career, which might be the case considering it wasn't too long ago that he was talking about playing into his mid-forties, ala Tom Brady. I don't think that will end up happening but he has the chance to stick around for at least another year.
The real issue is that the options are running out. Perhaps a team like the Houston Texans could make sense as they seem poised to take a quarterback after Davis Mills hasn't turned out. Outside of them, it is hard to see another team that fits that mold.