Which symbol among the given is a vowel?

• A. /u:/
• B. /v/
• C. /f/
• D. /s/

Answer: (A)

Vowels are sounds produced with an open vocal tract, allowing the air to flow with little constriction, and in IPA they are represented by vowel symbols that show the inherent qualities of a vocalic sound. The symbol /u:/ encodes a long high back rounded vowel, the kind of sound you hear in the word “goose.” Its features—high tongue position, back placement, rounded lips, and length—confirm it as a vowel symbol.

The other symbols are consonants because they involve some degree of constriction and friction in the vocal tract. /v/ is a voiced labiodental fricative, /f/ is a voiceless labiodental fricative, and /s/ is a voiceless alveolar fricative. These sounds are produced with a narrowing that creates friction, not with an open vocal tract like vowels. So the symbol that represents a vowel is /u:/, matching the sound category described.