Final answer:
All components such as your signature, your company's address or Letterhead, and your reader's address should be included in a business letter, thus the correct answer is D. All of the above.
Step-by-step explanation:
When composing a business letter, there are several essential elements that should be included. Among them are Your signature, Your company’s address or Letterhead, and Your reader's address. Therefore, the answer to the question should be D. All of the above. Including all these elements ensures that the letter is professional and contains all the necessary information for the reader to respond accordingly. Specifically, the parts of a cover letter generally consist of the sender's address, date, recipient's or inside address, greeting, body, closing, and signature, while also mentioning your name, typed out at the end. Moreover, if there are any enclosures, they should be listed after your typed name, denoted by the word 'Enclosures'.