Which of the following reduces the amount of data that must be transmitted on a network by keeping a copy of recently transmitted data in memory?

Latency is a measurement of network delay in milliseconds and is not a technique or mechanism - it does not reduce or control the amount of data transmitted.

Compression reduces the byte size of data before transmission but still sends data across the network on every request - it does not retain a copy in memory for reuse on subsequent requests.

Caching maintains a local copy of recently requested or transmitted data in high-speed memory such as RAM or a dedicated cache tier. When the same data is needed again, it is retrieved from the cache rather than fetched from the original source, eliminating the need to retransmit that data across the network. This directly reduces network utilization and improves response time for frequently accessed content.

Bandwidth describes the maximum data transfer capacity of a network link and is a property of the network itself, not a technique that reduces the volume of data that must be transmitted.