The following passage is adapted from Jerome K. Jerome’s novel Three Men in a Boat (To Say Nothing of the Dog). The narrator is on a boat trip with his friends. '[Harris] told us anecdotes of how he had gone across the [English] Channel when it was so rough that the passengers had to be tied into their [beds], and he and the captain were the only two living souls on board who were not ill. Sometimes it was he and the second mate who were not ill; but it was generally he and one other man. If not he and another man, then it was he by himself.' Which choice best describes the function of the underlined sentence in the text as a whole?