Concept:A vowel-sound matching question requires the reference word and the underlined letter(s) to identify the target sound.Explanation:The question gives no reference word and no underlined letters.So it cannot be compared with the options.The option words have distinct vowel sounds:A. peeve = /iː/B. stir = /ɜː/C. theft = /ɛ/D. slipped = /ɪ/Since the target sound is missing, more than one option could match a possible target.No unique option can be selected.Answer:Cannot be determined from the given information.