Answer:
A) He should include specific, verifiable facts.
Explanation:
Mark is a senior editor and is editing work written by Bruno.
He will want to provide an objective feedback to Bruno on his work that will not discourage him from doing his best. But also effectively state all the errors in the work that needs correction.
The best way to do this will be by including specific verifiable facts.
This will give a neutral response and maintain a good work environment.