Read the following announcement and mark the letter A, B, C, or D on your answer sheet to indicate the correct option that best fits each of the numbered blanks from 13 to 16.

CULTURE IN LETTER WRITING
1. When writing a formal letter, always include a polite ___(1)___ at the beginning of the letter.
2. It is essential to express gratitude and ___(2)___ for the recipient’s time and attention.
3. Make sure to sign off with a ___(3)___ closing, such as "Yours sincerely" or "Best regards."
4. When writing an informal letter to a friend, you can use a ___(4)___ greeting like "Dear [Name]."