Which of the following would not be a good supporting sentence for a process paragraph with the following topic sentence?

When mailing a letter, following these steps is necessary.

A. The United States Postal Service carries many letters and packages, so be careful not to make a mistake.
B. When mailing a letter, following these steps is necessary.
C. After placing the letter in an envelope, remember to seal the envelope carefully
D. Make sure to attach the proper postage amount in the top right-hand corner. Don't forget to write your return address!