OPTIONS: i. off road vehicles; ii. all-terrain vehicles; iii. autonomous controlled airplanes; iv. remote-control vehicles;

Answer the following question given this paragraph: 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. Q: What type of vehicles is able to go to the deepest ocean floor? A:
Answer:
iv.