Concept:The given phonetic symbol represents the long vowel sound /ɑː/. We need to identify the word whose pronunciation contains this exact sound.
Explanation:Let's examine the vowel sound in each word.
• pack: pronounced /pæk/, which has the short vowel /æ/, not /ɑː/.
• heart: pronounced /hɑːt/, which clearly contains the long vowel /ɑː/.
• player: pronounced /ˈpleɪər/, which has the diphthong /eɪ/ followed by a schwa, not /ɑː/.
• alone: pronounced /əˈləʊn/, which contains /ə/ and the diphthong /əʊ/, not /ɑː/.
Only the word "heart" has the /ɑː/ sound.
Answer:The correct option is B. heart.