Microsoft’s approach to transparency for AI-generated media relies on provenance signals rather than cosmetic indicators. File names and descriptions can be edited easily and are not reliable evidence of how an image was created. Watermarks may appear in some contexts, but they are not consistently applied across all AI image-generation workflows and can sometimes be removed or lost through copying, screenshotting, or file conversion.

Microsoft supports the use of content credentials to help users verify whether digital content was created or modified with AI. Content credentials are part of a provenance standard (often associated with C2PA) that can embed tamper-evident metadata into media files. When present, these credentials can show information about the tool or process used to generate or edit the image, providing a verifiable chain of origin.

Therefore, the most dependable way to verify whether the images were AI-generated is to check for content credentials (option C), since they are designed specifically to provide authenticity and provenance information for AI-created or AI-edited content.