When a third-party antivirus product must remain active, Microsoft Defender Antivirus should run in passive mode while Defender for Endpoint provides EDR capability. ForceDefenderPassiveMode is the explicit configuration used to keep Defender Antivirus passive and avoid conflict. Disabling the Defender for Endpoint service would remove EDR. EDR in block mode can add blocking behavior but does not by itself prevent antivirus coexistence conflicts during onboarding. The compute domain tests whether protection is applied before deployment, during runtime, or through posture assessment. The selected answer matches the phase described in the requirement. Detection-only tools are not acceptable when the requirement says prevent, and local installation methods are inferior when Defender for Cloud, Azure Policy, or Azure Machine Configuration can enforce the control centrally. The result is a direct exam-style implementation choice: it changes the required security behavior without relying on unrelated monitoring, manual cleanup, or excessive privilege. Official Microsoft source/topic: SC-500 Study Guide > endpoint detection and response; Microsoft Learn > Microsoft Defender Antivirus passive mode.

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