Question

what tectonic activity would cause a deep ocean trench to form? plates colliding with one another plates remaining in a stable position plates moving away from one another plates rubbing against each other

Explanation:

Deep ocean trenches are formed at convergent plate boundaries where one tectonic plate subducts beneath another as they collide. Plates remaining in a stable position don't cause such features. Plates moving away create mid - ocean ridges and plates rubbing against each other cause faults and earthquakes mainly, not deep ocean trenches.

Answer:

plates colliding with one another