In which line from the excerpt does Sherlock Holmes acknowledge that Dr. Watson is his foil?
O "I have, at least, a well-polished, silver-plated coffee-pot in front of me."
O "I am bound to say that in all the accounts which you have been so good as to give of my own small
achievements you have habitually underrated your own abilities."
O "So your grave, middle-aged family practitioner vanishes into thin air, my dear Watson, and there
emerges a young fellow under thirty, amiable, unambitious, absent-minded, and the possessor of a
favourite dog, which I should describe roughly as being larger than a terrier and a smaller than a
mastiff."
O "I am afraid, my dear Watson, that most of your conclusions were erroneous. When I said that you
stimulated me I meant to be frank, that in noting your fallacies I was occasionally guided towards the
truth."