The correct answer is 'Security camera footage showing a person accessing a restricted area.' This demonstrates non-repudiation because the video provides clear evidence that a specific individual accessed a restricted area and the action cannot be denied. This aligns closely with the criteria of non-repudiation where the proof of an action is undeniable. The other responses are incorrect: 'Video call logs' and 'Download history of video files' do not provide irrefutable evidence of an individual's actions in a high-security context, and 'Favorited videos on a streaming platform' is related to personal preferences, not security incidents.