In my opinion, the correct answer is C. tone. Intention has to do with the prewriting process; if I intend to do something, it doesn't mean I will be able to achieve it. On the other hand, my tone can be comical, tragical, sarcastic, skeptical... It is my choice of stylistic devices that I intentionally use to show exactly how I feel about the topic. My writing voice consists of all the elements that make my writing unique and recognizable, distinct from all other authors. Euphemism has nothing to do with these things, it is simply an expression which is intentionally milder than it should be.
