The correct answer is B. Your ensemble for the costume party was so well designed that I did not recognize you.
Explanation:
In communication, the tone of the speaker refers to the attitude the speaker has which is determined by the election of words, point of view and use of language. In the case of formal tone, it differs from the informal tone and other types of tones because the speaker chooses sophisticated and formal words, longer and complex sentences and avoids informality such as direct judgments, use of slangs, word contractions or rude words. Additionally, this tone is used in certain contexts such as job or academy and it shows the speaker is educated and serious. Considering this, the statement with the most formal tone is "Your ensemble for the costume party was so well designed that I did not recognize you" because this statement is the one in which sophisticated language is used, for example instead of saying "custom" the speaker uses the expression "ensemble for the costume party". Also, in this statement, the sentences are longer and complex and the speaker avoids contraction, rude words and any other informality.
A thesis statement is one sentence that expresses the main idea of a research paper or essay, such as an expository essay or argumentative essay. It makes a claim, directly answering a question.