Concept:The vowel sound needed is the long /uː/ sound.Explanation:The underlined letters in the question word are pronounced like the vowel sound in "choose".The word "book" has the short /ʊ/ sound, not /uː/.The word "fool" has the long /uː/ sound, so it is the correct match.The word "comb" contains the /əʊ/ sound.The word "bomb" contains the /ɒ/ sound.Hence, only "fool" shares the same vowel sound.Answer:B. fool