What file formats can users upload for their own floorplans in Cvent Event Diagramming?

The correct answer identifies the specific file formats that are compatible with Cvent Event Diagramming for users to upload their own floorplans. Cvent allows uploads of .pdf, .png, and .jpeg formats, which encompass popular image and document formats that support high-quality visuals necessary for diagramming.

PDF files are particularly useful as they can maintain the quality of design elements and scaling, making them ideal for detailed diagrams. PNG and JPEG formats are commonly used for images, providing a balance of quality and file size, which is advantageous when uploading images of floor plans or layouts.

The other options include formats that are either not supported for this specific use case, such as .txt, .gif, .docx, .jpg, and .xlsx, or do not provide the appropriate quality and detail required for effective event diagramming. Thus, option C stands out as the only choice that aligns with the requirements for uploading custom floorplans in Cvent.