Concept:The underlined letters "ng" stand for the single nasal consonant sound /ŋ/.
This sound is produced from the back of the mouth against the soft palate.
Explanation:The word "lung" is pronounced as /lʌŋ/.
Its final consonant sound is exactly /ŋ/, which matches the underlined "ng" sound.
Now check the other options.
"dig" ends with the sound /g/, which is a hard stop, not a nasal.
"sin" ends with the sound /n/, a different nasal sound made at the front of the mouth.
"tag" also ends with /g/, just like "dig", so it is not correct.
Only "lung" contains the same final consonant sound /ŋ/ as the underlined letters.
Answer:D. lung