Final answer:
The level of review formality is determined by the amount of preparation, reviewer follow-up, and structure review.
Step-by-step explanation:
The level of review formality is determined by the amount of preparation, reviewer follow-up, and structure review. These factors influence the extent to which a review process is conducted in a formal or informal manner. For example, if there is a thorough preparation and follow-up from the reviewer, along with a structured review process, the level of formality would be higher. Therefore, the correct answer is 5) a, b and d.