All of the above
Tidal forces acting on planets tend to change their rotational speeds in various ways. The Moon is acting on the Earth's oceans and atmosphere, as well as the plastic portions of the Earth's interior. The gravitational drag slows the Earth down, and also acts on the lunar orbit. Without going into extensive details, at some point in the unimaginable future, the Earth will have a day about one lunar month long, i.e. the Moon will always be in the same spot in the sky. The Moon will also be a lot further away.