Final answer:
The notation for indicating items included with a letter is b) 'Enclosure.' It's listed under the sender's typed name and ensures that the recipient is aware of additional documents.
Step-by-step explanation:
The notation used to indicate that something is included inside the envelope with the letter is b) Enclosure.
When you have additional items to send with your letter, such as a resume or a writing sample, you can list these by writing the word "Enclosures" one line below your typed name at the end of the letter.
It is important to ensure that you have permission to share any work with others if it was done for a company, as you should respect copyright and confidentiality agreements.