Concept:The underlined letters "aw" in "pawn" represent the long vowel sound /o:/.Explanation:The word "pawn" is pronounced as /po:n/.Its vowel sound is /o:/.The word "call" is pronounced as /ko:l/, which contains the same vowel sound.The other options have different vowel sounds: "word" has /3:/, "won" has /^/, and "sown" has /oʊ/.Answer:B. call