Final answer:
The trait that is NOT valuable for a person handling emergency calls is an inability to retain composure as it is essential to remain calm and make quick decisions in such scenarios.
Step-by-step explanation:
The valuable characteristics or traits for a person who receives emergency calls include the ability to perform multiple tasks, the ability to remember details and recall information easily, and the ability to exercise voice control. However, an inability to retain composure is not considered a valuable trait for an emergency responder; in fact, it is a detrimental characteristic. Emergency situations require a calm and composed response to make fast, efficient decisions.