ㄹ지 정하다

decide what, where or who

An embedded question feeds straight into 정하다, to settle on something: decide where to go, decide what to do, decide who will present, decide whether to use casual or polite speech, decide where to live from now on. Three of these lines settle it by rock-paper-scissors, which is the usual way of deciding who has to do a thing. The question word inside is what makes this different from just choosing.

Register: casual