Concept:This question tests your ability to identify the same vowel sound in different words.Explanation:The word pearl is pronounced /p3:l/, and the underlined letters give the vowel sound /3:/.Curtain is pronounced /’k3:t@n/, so it also contains the same vowel sound /3:/.Fear has the sound /I@/, care has the sound /eε/, and sergeant has the sound /a:/.None of these matches the vowel sound in pearl.Hence, the correct option is curtain.Answer:A. curtain