Answer:
d. Notations
Step-by-step explanation:
On a business letter, any items in addition to the letter are notated at the end of the letter. This is called an Enclosure Notation, and it lets the reader know that there is additional information included in the letter. They are notated at the end of the letter by "Enc." or "Enclosure(s)" after a blank space under the sender´s name and/or signature.