The most likely outcome regarding Triton's interaction with Neptune's gravity is:
D. Triton will become a ring around Neptune.
Triton is slowly spiraling inward towards Neptune due to tidal forces. Over a long period, this could lead to Triton breaking apart due to tidal forces if it gets too close to Neptune, eventually forming a ring system around the planet. The other options are less likely given the current understanding of Triton's orbit and interactions with Neptune.