STIX/TAXII are industry-standard protocols for structured threat intelligence exchange. According to the Threat Intelligence section of the XSOAR documentation, TAXII servers and clients provide automated bidirectional sharing using STIX objects, supporting both ingestion and distribution of indicators, observables, relationships, and threat objects.
The TAXII Server content pack specifically enables an organization to expose its threat intelligence via a TAXII 2.0/2.1 compliant endpoint, where the transmitted data is formatted as STIX, making it the correct choice for sharing structured intelligence externally.
The Generic Export Indicators Service pack supports indicator export, but not in STIX format—it exports simple CSV, JSON, or list-based formats. MISP Server supports STIX ingestion and export but is considered a MISP-specific implementation and not the generic STIX distribution mechanism expected in the question. External dynamic lists are not related to STIX or TAXII at all.
Thus, the correct answer is D, as only the TAXII Server pack is designed explicitly for STIX-formatted intelligence sharing.