Delete "Being late to school is a major bummer." in the second paragraph
Change "I'm" to "I am" in the third paragraph.
Step-by-step explanation:
A formal letter should have the following:
1. Sender address with date
2. Receiver's address
3. Greeting
4. Subject
5. Body of the letter
Delete "Being late to school is a major bummer." in the second paragraph : This option stands right according to the given choices because, we have this being mentioned in one the paragraph. ("create major delays for students"). So it would be repetitive and hence can be deleted.
Change "I'm" to "I am" in the third paragraph.
Normally in formal letter, we avoid writing in short forms. So we can use this option of writing in an expanded way.