Distributed broker clusters give inter-agent traffic backpressure, replication, and topic partitioning without creating an all-to-all TCP mesh. Polling a database adds avoidable latency and operational noise. The correct implementation surface is a separated data plane where ingestion, indexing, retrieval, reranking, and generation can each be measured and updated. The selected option specifically C states "Event-driven message routing with distributed broker clusters", which matches the operational requirement rather than a superficial wording match. The architecture implied by Option C is the one that survives real workloads:
separate responsibilities, explicit contracts, and measurable runtime behavior. The alternatives would look simpler in a prototype, but synchronous monoliths make freshness and latency fight each other because indexing and generation cannot scale independently. In NVIDIA terms, a production RAG workflow should treat the retriever as a measurable service, not as an invisible prelude to LLM generation. This choice gives engineering teams the knobs they need for continuous tuning after deployment.