In the following question out of the five alternatives, select the alternative which best expresses the meaning of the idiom/phrase.
Its an old trick I learned a long time ago, sometime I'll teach you, but right now we have a bigger fish to fry.
The idiom 'have bigger fish to fry' means 'have other more important matters to attend to.'
For e.g.: I would love meet you at the bar, but I have bigger fish to fry tonight.
So, option 5 is correct.