Which of the following is essential when writing a letter?

Clearly addressing the recipient is essential when writing a letter because it establishes the intended audience and ensures that the message reaches the right person. A well-addressed letter demonstrates professionalism and respect for the recipient. It helps to create a connection between the writer and the reader, setting the tone for effective communication. Ensuring the recipient's name and address are accurately stated prevents misunderstandings and allows the correspondence to be delivered properly.

In contrast, while background information can provide context and enhance communication, it is not always necessary for every letter. Elements like plot twists and complex vocabulary may not contribute to the clarity or purpose of a letter. In fact, simplicity and directness are often more effective in personal or professional correspondence.