What is the prediction for the future of Triton?
A. It will crash into Nereid when the smaller moon comes too close.
B. It will develop active volcanoes as Neptune's tidal stresses become greater.
C. Its retrograde orbit will throw it back out into the Kuiper Belt again, with Pluto.
D. Its orbit, while retrograde, is very stable and will not change.
E. It will provide the raw material for a future Neptunian ring.
