Concept:This question tests the ability to recognise the same consonant sound even when it is represented by a different letter or group of letters.
Explanation:The word "fly" is pronounced /flaɪ/.
Its underlined letter "f" gives the consonant sound /f/.
Now, check the pronunciation of each option to find the same sound.
"tough" is pronounced /tʌf/.
The letters "gh" in "tough" produce the /f/ sound at the end of the word.
This exactly matches the /f/ sound found in "fly".
"though" and "dough" are pronounced /ðoʊ/ and /doʊ/ respectively.
In both words, the letters "gh" are silent, so there is no /f/ sound.
"revive" is pronounced /rɪˈvaɪv/.
Its consonant "v" represents the voiced sound /v/, not the voiceless /f/ sound.
Therefore, "tough" is the only option that contains the same consonant sound /f/ as the underlined letter in "fly".
Answer:A. tough