Which of the following serves to balance traffic load for downloads?

Using a mirrored site effectively balances traffic load for downloads by creating an exact replica of a website or service on a separate server. This approach allows the distribution of incoming requests across multiple servers, which can reduce the load on any single server and enhance performance. When users download files or access resources, they can be directed to the nearest or least busy mirrored site, ensuring quicker access and improved reliability. This method also enhances redundancy, as if one mirrored site faces high traffic or downtime, users can be rerouted to another, maintaining accessibility and performance.

In contrast, a cloud storage service primarily provides centralized data access rather than optimizing download traffic across multiple locations. An antivirus program focuses on protecting systems from malware rather than managing traffic loads and ensuring efficient file downloads. A local backup server is intended for data storage and recovery within a specific network environment but does not play a role in balancing traffic for downloads, as it serves to restore data rather than distribute requests among multiple access points.