Instructions: Given a scientific passage and an answer, generate a question for the given answer.
Input: Passage: Today, remote-control vehicles, called remotely operated vehicles (ROVs) go to the deepest ocean floor. They don't have any people on board. However, they carry devices that record many measurements. They also collect sediments and take photos. Answer: remote-control vehicles
Output:
What type of vehicles is able to go to the deepest ocean floor?