Which of the following is the best example of a formal tone?

ABeat the eggs for two minutes until they're frothy and foamy. Then pour them into the greased pan.

BBrandy's dad gave her the most awesome present for her birthday- a trip to Cancun.

CThis is to inform you that your book has been rejected by our publishing company.

DYou know that party we crashed? Well, the cops shut it down after we left.