Final answer:
Adobe's proprietary RAW file format is the Digital Negative (DNG) which is intended to be a universal RAW file format for digital cameras.
Step-by-step explanation:
Adobe created the Digital Negative (DNG) format as their own proprietary RAW file format. The correct answer to the question is c) DNG. Unlike other camera-specific RAW formats like CR2 (Canon), NEF (Nikon), and ORF (Olympus), DNG is intended to be a universal RAW file format that can be used across different models and brands of cameras. Adobe's goal with DNG was to provide an open archival format for the raw files generated by digital cameras. While not all camera manufacturers have adopted DNG as their native RAW file format, Adobe offers a free DNG converter that can convert proprietary RAW files to DNG files. This helps to ensure long-term accessibility of the files as technology evolves.