正解:C
The greatest benefit of having a mature enterprise architecture (EA) in place is efficient operations, as EA provides a holistic view of the organization's business processes, information systems, and technology infrastructure, and enables alignment, integration, and optimization of these components. Standards-based policies, audit readiness, and regulatory compliance are also benefits of EA, but they are not the greatest benefit. References = CRISC Review Manual, 7th Edition, page 145.