Given the task definition and input, reply with output. Given a scientific passage and an answer, generate a question for the given answer.

Passage: mid-ocean ridges : A long chain of mountains that rises up high above the deep seafloor. An example is the light blue gash in middle of Atlantic Ocean. Light blue is higher elevation than dark blue. Answer: mid-ocean ridges

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
A long chain of mountains that rises up high above the deep seafloor is called?