A supported model repeatedly receives the same long instruction prefix followed by a different user question. The provider offers prompt caching for qualifying prefixes. Which statement best describes the potential benefit?

1. It automatically removes all authorization requirements for the cached source content.
2. It guarantees that every different user question receives a precomputed final answer.
3. Eligible repeated prefix processing can be reused under the supported cache rules, potentially reducing input-processing cost or latency.
4. It permanently fine-tunes the model weights with the cached instruction prefix.