Final answer:
Tightening your message means to consolidate your writing to be succinct, involving proofreading for concise expression and omitting superfluous details.
Step-by-step explanation:
“Tightening” your message generally means making your writing more concise and to the point. This involves proofreading to eliminate errors, cutting out unnecessary background information, and ensuring that each word and sentence effectively contributes to communicating your message. Amongst the options given, the closest to the concept of tightening a message is C. Looking for shorter ways to say what you mean, though it should be noted that this also involves elements of option D, which is cutting out unnecessary background information.
When you proofread and revise your writing, you are looking to polish your message. This means clarifying and defining concepts, smoothing out rough spots, and being more accurate. You should also correct errors, cut out any fluff, and look for ways to improve sentence variety and structure for more effective communication.
Lastly, it's important to ensure that your writing adheres to the “Editing Focus”, which includes using words correctly, maintaining verb tense consistency, and using transitional words and phrases where appropriate. Through careful proofreading, you can catch minor typos, spelling mistakes, and punctuation errors that might distract from your message.