It seems that you have missed the necessary options for us to answer this question, but anyway here is the answer. The sentence from the passage that explains what the main characters do in Rosencrantz and Guildenstern are dead is this: "As in Beckett's play, Rosencrantz and Guildenstern pass the time by impersonating other characters, engaging in word play, and remaining silent for long periods of time." Hope this helps.
