This excerpt narrates how the man and woman arrive to the top of the mountains, tired and beat. So they explain through really predictable words such as: exhausted, went to sleep... and also their desperation to get some rest when they say: <em>"I took a buffalo rope from the packs and wrapped myself in it..."</em>
It would be C. finally because chronologically refers to in a timely order (first, next, then, ect.) and finally is a concluding word that also refers to the chronological style of writing.
