The correct answer is Asset owner.

The Asset owner is accountable for the information system or asset and must provide the evidence that security controls are implemented and operating effectively during the control assessment. The owner is responsible for maintaining and supplying system level artifacts such as configuration records, operational procedures, and evidence of control operation so assessors can evaluate control effectiveness.

Independent security control assessor is incorrect because the assessor tests and evaluates the evidence and produces an assessment report but does not supply the primary evidence of control implementation. The assessor validates what the owner provides rather than originating those artifacts.

Security program manager is incorrect because the program manager oversees enterprise security policy and coordination but does not usually own specific systems and therefore is not the primary source of implementation evidence for a given asset. They may help coordinate assessments but they do not provide the system level control artifacts.

Designated approving authority is incorrect because the approving authority or authorizing official makes the risk acceptance decision based on assessment results and evidence but is not the party responsible for supplying the evidence that controls are implemented. They rely on the assessment and owner-supplied artifacts to make their decision.

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