Concept: The underlined letter in each word represents a vowel sound; we must match the exact vowel sound of bull.Explanation:The word bull is pronounced as /bul/. Its underlined vowel sound is /υ/, which is a short, relaxed vowel sound. Now check each option: hoof can be /huf/ or /hu:f/, but the standard given sound is /hu:f/. crude is /kru:d/; its vowel sound is /u:/. soup is /su:p/; its vowel sound is /u:/. stood is /stud/; its vowel sound is exactly /u/. Therefore, stood shares the same vowel sound as bull.Answer: D. stood