I think the answer is either
A. Why does Harry seem sad at the end of the passage.
or
D. Where will jack and Harry find work after the professor leaves?
The letter from Samuel Johnson shown above was made as a refusal to request a woman who would like to receive sponsorship from a bishop to send her son to university.
In the Letter, Johnson explains the reasons that led him to reject this request, stating that they cannot ask the bishop he does not know, sponsorship for a boy the bishop does not know. This is because this type of sponsorship was something very big, with great economic expense. Therefore, this was not offered to strangers, but only to people with whom the sponsors had knowledge and a certain intimacy.
In this letter, Johnson makes recurring use of ethos and logos. He uses ehos, when he shows that he is rejecting the request in the most ethical and respectable way possible, and, he uses logos, when he shows that the refusal is not being made for personal reasons, but for the logic of the situation.
Finally, Johnson says that he believes that the woman's son is a brilliant boy and that it is not necessary for him to go to university to be a great man.
If you want to explain to a foreigner how to learn when to use these words, you can say that the go from more general to more specific (in: more general, at: more specific).
in: for objects inside other objects, or for location in a big context: year, country,
on: on top of other objects, or for location in middle-scale contexts: day, street
at: for location on a very small scale: moment (exact time), at specific address<span />