5 Rules of Email Etiquette Don't assume you're on a first-name basis with the person you're emailing. We've all been told that maintaining the highest level of formality in professional email correspondences is important. ... Cut the informal language. ... Don't leave the “Subject” field blank. ... Compose a new email when you need to. ... Mind your manners.
The answer is A because the last 2 answers especially the third one is a bad answer choice because if you start an essay as so like "this essay will be about blah blah" you don’t need that because later on the readers will know what the essay is about.