The author advances the plot through the use of the narrator's .
a) discussion with peers in a medical library
b) page-by-page study of a medical text
c) detailed recollected of his doctor's advice
d) struggle with painful physical symptoms
(this is from the article: three men in a boat by Jerome K. Jerome)

struggle with painful physical symptoms

Explanation:

remember that he went to the british museum, and he was trying to read up the treatment for his fever, but then read more and self diagnosed himself with almost everything in the book, it was never his doctor who diagnosed him with all these diseases. (not fully sure, this is just a guess)

can you say more details