The correct option is C Student's name and signature
Formal letters are usually written in this format:
The sender's address,
Date.
The receiver's address,
Salutation
Subject (sometimes the subject is not included)
Body of the letter
Appropriate close (Thank You)
Closing salutation (Yours sincerely)
Name and signature
Title (if applicable)
Option A: The letter ends with a suitable closing, including 'Thank You' and 'Yours sincerely'. This is followed by the student's name and signature.
As the options do not mention the closing, 'the student's name and signature' is the most suitable option that fills blank 25. Hence A is correct.
Option B: The place is not included in the closing of a formal letter. Hence B is incorrect.
Option C: The sender's address is written in blank 21, and not in 25. Hence option C is incorrect.
Option D: The receiver's address is written in blank 23 (after the date), hence D is incorrect.