Which of the following is an important feature of a well-structured letter?

A cohesive connection between the letter parts is vital for ensuring clarity and coherence throughout the communication. Letters serve specific purposes, whether they're formal or informal, and having a clear structure with well-connected sections allows the reader to easily follow the thoughts being expressed. Each part of the letter—including the introduction, body, and conclusion—should relate logically to the others, helping the reader to understand the message as a whole. This structure enhances readability and ensures that the communication is effective and serves its intended purpose.

In contrast, including multiple ideas in each paragraph can lead to confusion and makes the letter harder to follow. While formal language is important in certain contexts, not all letters require a strictly formal tone, and a casual tone is not always appropriate, especially in formal communication. Thus, the option emphasizing the cohesiveness of the letter as a whole aligns with the essential principles of effective written communication.