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 is leaving the country for a good.

A for better prospects

B for a good cause

C for ever

D for others good

ANS:C - for ever

No answer description is available.