Directions: Choose the option that best expresses the meaning of the idiom which is underlined.

The Chief Minister had the Inspector-General of Police to fill him in on the behavior of the arrested terrorists.

'Fill someone in' is an idiomatic expression meaning to provide someone with information or update them about something. In this context, the Chief Minister wanted the Inspector-General to inform him about the terrorists' behavior. 'Probe into cases' means investigate, 'take action against' means punish, and 'to punish' is too specific.