Final answer:
The Bronze level QoS option provides 'Best Effort' service, which is the most basic form with no guarantee of performance factors such as bandwidth or delay.
Step-by-step explanation:
The QoS (Quality of Service) option that provides "Best Effort" service is typically referred to as the Bronze level. In the context of QoS, "Best Effort" is the lowest level of service, which means that traffic is treated on a first-come, first-served basis without any guarantee of bandwidth, delay, or delivery. Among the options provided, including Silver, Gold, and Platinum, the Bronze level corresponds to the "Best Effort" service.