What color bubble indicates that an e-mail in thread views is inclusive and NOT a duplicate?

The correct answer identifies the color associated with an email that is inclusive, meaning it is part of a thread view yet is not a duplicate. In this context, the blue bubble signifies that the email is important and adds value to the conversation, distinguishing it from duplicates of previous messages.

Selecting the blue bubble helps users quickly discern which emails provide unique content or contributions within a thread, making it easier to track the flow of discussion. Utilizing color coding such as this improves efficiency in managing email communications, as it allows users to prioritize which messages to focus on without wasting time on identical copies.

The rationale for the other color options not representing inclusive emails is that each likely serves a different purpose within the email system's organizational structure, such as identifying urgent matters or categorizing other types of correspondence.