What type of geological activity is seen on Neptune's moon Triton?

Question

1. Plate tectonics and earthquakes are a common occurence on Triton.

2. Volcanoes of molten lava, similar to Earth, have been seen there.

3. Geysers of liquid nitrogen are seen erupting from its surface.

4. Geysers of liquid water are seen erupting from its surface.

Answer 1

Yeah.  3.  The Voyager 2 spacecraft snapped pictures.

Voyager 1 didn't get to Neptune because it was diverted to a closer flyby of Saturn's moon Titan.

Answer 2

3.