Idioms and Phrases - Verbal and Reasoning

In the following questions four alternatives are given for the idiom/phraseitalicised and underlinedin the sentence. Choose the alternative which best expresses the meaning of idiom/phrase.
Q1:

He did me a good turn by recommending me for the post of Vice Principal.

A returned my kindness

B did an act of kindness

C improved my prospects

D became suddenly good

ANS:B - did an act of kindness

No answer description is available.