The System Owner (or Information System Owner) is a managerial role with ultimate responsibility for an information system throughout its lifecycle. Their responsibilities encompass procurement, development, operation, and disposal.

Option A is correct as it addresses the crucial lifecycle responsibility of integrating security from the very beginning. Option B correctly identifies the owner's duty to ensure ongoing security posture management, including vulnerability assessments and reporting. Option D provides a concise, high-level summary of the System Owner's core accountability for ensuring the system complies with security requirements, as explicitly defined in NIST frameworks.

C. This option is incorrect because it conflates the managerial oversight of the System Owner with the specific, hands-on technical tasks of a System Administrator or Custodian. While the owner ensures security policies are met, they do not typically oversee the granular details of "operating system configurations."

1. NIST Special Publication 800-53, Revision 5, Security and Privacy Controls for Information Systems and Organizations. (December 2020).

Appendix F, Section F.2.6 (Information System Owner): States the System Owner is "Responsible and accountable for ensuring that the security and privacy of the information system are adequately addressed throughout the life cycle... [and] for ensuring that all security and privacy controls are implemented and operating as intended." This directly supports option D. It also supports the lifecycle concept in option A.

2. NIST Special Publication 800-18, Revision 1, Guide for Developing Security Plans for Federal Information Systems. (February 2006).

Section 2.2 (Roles and Responsibilities), System Owner: Defines the role as the "official responsible for the overall procurement, development, integration, modification, operation, maintenance, and disposal of an information system." This supports option A (procurement, development) and the operational oversight implied in option B.

3. Carnegie Mellon University, Information Security Office, Information Security Roles and Responsibilities. (2023).

System Owners Section: Lists responsibilities including: "Ensuring that appropriate security controls are in place and functioning as intended" (supports D), "Ensuring that the system is regularly scanned for vulnerabilities" (supports B), and "Ensuring that security is a part of the system's entire life cycle" (supports A). This source clearly delineates these high-level responsibilities for the owner.