What aspect of communication ensures that unnecessary information is excluded?

The correct answer is conciseness. Conciseness in communication refers to conveying information clearly and directly while avoiding unnecessary details or filler. By being concise, the communicator focuses on the essential elements of the message, thereby enhancing understanding and allowing the recipient to grasp the main points without distraction.

Cohesiveness pertains to the logical flow and connectedness of ideas within communication, ensuring that all parts of the message relate to one another. Clustering refers to grouping related information together, which can aid in clarity but does not specifically address the exclusion of unnecessary information. Congruency involves the alignment of verbal and non-verbal communication to convey a consistent message, which is important for effective communication but does not directly relate to filtering out extraneous content. Thus, conciseness is the key aspect that ensures only the most relevant information is shared, making communication more effective.