Concept:The sound /s/ is a voiceless consonant sound commonly represented by the letter "s".Explanation:Check each option for the presence of the /s/ sound.A. "cash" is pronounced /kæsˇ/: it contains no /s/ sound.B. "church" is pronounced /tS3:tS/: it contains no /s/ sound.C. "slash" is pronounced /slæsh/: it begins with the /s/ sound.D. "bees" is pronounced /bi:z/: it ends with a /z/ sound, not /s/.Therefore, the word that contains the sound /s/ is "slash".Answer:C. slash