The correct answer is A.
OBJ-2.1: The MITRE ATT&CK framework provides explicit pseudo-code examples for detecting or mitigating a given threat within a network and ties specific behaviors back to individual actors. The Diamond Model provides an excellent methodology for communicating cyber events and allowing an analyst to implicitly derive mitigation strategies. The Lockheed Martin cyber kill chain provides a general life cycle description of how attacks occur but does not deal with the specifics of how to mitigate them. OpenIOC contains a depth of research on APTs but does not integrate the detections and mitigation strategy.