Everything was metal , and there was no mattress . He got up to open the door , and found it locked or blocked or something from the other side . That meant , then , that someone played a trick on him . He almost took his shirt off and set fire to that , but he needed the warmth it provided , scant as it was . So , instead , he banged on the door .

Question: Why is burning his shirt impractical in this situation ?
Answer: He is not wearing a shirtNone of the above choices .His shirt is made of a material that is hard to burnThe room is flammable and will burn