Please choose the correct answer to the question: The Mariana Trench is the deepest ocean trench on Earth. This trench occurs at a plate boundary where

Answer1: one plate is sliding past another. Answer2: one plate is being forced beneath another. Answer3: two plates are colliding into each other. Answer4: two plates are pulling apart from each other.

Answer format: answer1/answer2/answer3/answer4
Answer: answer2