Explanation
To make sure all files are scanned locally upon execution, the administrator needs to set the On-Access File Scan Mode to Aggressive. This setting will scan all files on execute, regardless of whether they are new or pre-existing on the device. The assigned reputation and policy rules will apply to the scanned files. The other options are incorrect because they are not necessary to complete this task. Option B is incorrect because the Signature Update frequency is not related to the local scanning of files upon execution. It is related to how often the sensor checks in for signature pack updates. Option C is incorrect because the Allow Signature Updates is not related to the local scanning of files upon execution. It is related to enabling or disabling signature updates for the scanner. Option D is incorrect because the Run Background Scan is not related to the local scanning of files upon execution. It is related to enabling or disabling a one-time background scan on any endpoint sensorassigned to a policy. References: Configure Local Scan Settings, Endpoint Standard: How To Configure Local AV Scan