The correct answer is A. To inform the readers about how they set up their tent
Step-by-step explanation:
In the excerpt presented, the narrator or author describes different actions he and his team had to to in order to set up their tent and survive this includes details such as "we tried to build up the platform on the downhill side" or "we were buffeted by wind and snow" that describe the difficulties while trying to set up the tent and at the same time the need of this tent "our tent was our only chance of survival against the rigors of the night". This shows the purpose of this excerpt is not to entertain or persuade the reader but to inform or explain all the actions that were necessary to set up the tent or "to inform the readers about how they set up their tent".