Which occurs at a convergent boundary where one plate moves under another plate?
a. mid-ocean ridge
b. folds
c. rift valley
d. deep sea trench

d. deep sea trench

Explanation:

    Ocean-continent convergence: if a plate has a continental edge, it rides the ocean plate, because the continental crust is lighter and subdues more easily than the oceanic crust. The continental border is wrinkled and rises in a mountain belt, parallel to the deep sea trench. The enormous forces of collision and subduction produce great earthquakes along that limit. The west coast of South America, where the South American Plate collides with the Nazca Plate (oceanic), is a subduction zone of this type. The Andes mountain range rises on the continental side of the border, with active volcanoes and large-scale earthquakes.