A RAG assistant gives an incomplete policy answer. Review shows that the correct policy exists in the source collection, but none of its relevant passages appeared in the context sent to the model. What should the team investigate first?

1. Remove all metadata filters permanently, regardless of document access permissions.
2. Only the response wording style, while leaving the missing evidence problem unchanged.
3. Only the maximum answer length, assuming a longer response recovers documents the model never received.
4. The retrieval process, including ingestion, chunking, query matching, and applicable access filters.