Answer; The author is suggesting that most of the time when people envy it is not pure....
Explanation:
A and C are correct options.
There is no need to imitate Reagon and it will make it just an audio tape. Also, no need to add slangs as there would be teachers and other members there.
Vain is the correct answer. Plug in each word given into the sentence and then read it to see if the sentence makes sense.
"We may try in credibility to solve our problems on our own.." Credibility is incorrect.
"We may try in predict to solve our problems on our own.." Predict is incorrect.
"We may try in forgive to solve our problems on our own.." Forgive is incorrect.
"We may try in vain to solve our problems on our own.." Vain is correct!
Hope this helps! (: