The answer to your question would be that the line that is an example of euphemism is the following one: Let's just say I liked Latin but Latin didn't much care of me. That is, your answer would be C.
Euphemism refers to polite, indirect expressions that replace words and phrases that are considered impolite or even harsh. It is an idiomatic expression which loses its literal sense and refers to something else to avoid the harsness. It's impossible for Latin not to like somebody because it is not a person, it does not have volition. What the sentence really means is that the speaker didn't do well when learning that language.