Question

the peru - chile trench is a deep - sea trench that extends along the western coast of south america. here, the nazca plate is moving toward the south american plate at a rate of about 7.9 centimeters per year. as these plates collide, the oceanic crust of the nazca plate subducts, or sinks, below the continental crust of the south american plate, forming the peru - chile trench.
complete the sentence.
the peru - chile trench formed at a ______ boundary.
convergent
divergent
transform

Explanation:

The text states the Nazca Plate collides with and subducts under the South American Plate, which is the defining feature of a convergent plate boundary. Divergent boundaries involve plates moving apart, and transform boundaries involve plates sliding past each other, neither of which matches the formation of the Peru-Chile Trench.

Answer:

convergent