Deep-ocean trenches are most abundant around the rim of what plate?
The Pacific Plate.
The Atlantic Ocean is formed by a divergent boundary the European,Asian plates are moving East and the North American plate is moving west. There are no deep ocean trenches that are formed by subduction zones.
The Pacific Ocean is formed by a divergent boundary but the Pacific Plate unlike the Atlantic ocean crust is not connected to any continental crust. When the expanding Pacific Crust meets the North American, South American, and Asian Crusts subduction zones are formed. The Pacific Crust is pushed under the colliding continental crusts this forms subduction zones. The subduction zones create the deep ocean trenches.
The Pacific Ocean collides with Continental crusts creating subduction zones that form the deep ocean trenches.