Answer the following question: Fact 1: Aairplane is used for moving people across bodies of water. Fact 2: Most airplanes use gas turbines. Given the two facts above, _ are used for moving people across bodies of water.?

OPTIONS:
(I) dolphins.
(II) engines.
(III) gas turbines.
(IV) electricity.
(V) streams.
(VI) rivers.
(VII) arteries.
(VIII) animal transport.
Answer:
(III)