One is -sub An example if a word with the directional prefix -sub is submarine How it changes the root word (marine) is, marine means: of, found in, or produced by the sea . Submarine means:<span>a warship with a streamlined hull designed to
operate completely submerged in the sea for long periods, equipped with
an internal store of air and a periscope and typically armed with
torpedoes and/or missiles So marine has to do with a person, while submarine has to do with a warship
So you're looking for 2 synonyms. B is the best answer, avert and prevent are synonyms of each other. The other choices are antonyms, or they're at least not synonyms.
