Final answer:
The best revision to improve the formality of the paragraph is to emphasize positive acceleration.
Step-by-step explanation:
The best revision to improve the formality of the paragraph is option c) Emphasize positive acceleration.
To make the paragraph more formal, we need to focus on using language that is appropriate for an academic tone. Option c) Emphasize positive acceleration aligns with this goal by using more formal and objective language.
For example, instead of using subjective experiences (option b), we should prioritize using objective facts and evidence. Similarly, removing complex vocabulary (option a) can make the paragraph more accessible, but it doesn't necessarily make it more formal.