Wikipedia says the SNES port of Street Fighter Alpha 2 used the S-DD1 chip for graphic decompression.
The S-DD1 was a Nintendo-designed ASIC that dynamically decompressed graphics data while the game was running. That allowed Capcom’s port to fit large amounts of compressed sprite data into an SNES cartridge while sending the decompressed graphics to the console’s picture-processing hardware.
Street Fighter Alpha 2 was released for the Super Nintendo in 1996, a demanding conversion of a game originally built for arcade hardware. The port still had compromises, including loading pauses while sound data was transferred to the SNES audio system, but the specialized chip helped make the graphics possible.
The other options are different SNES enhancement chips or technologies. DSP-1 supported calculations such as those used in some 3D effects, SA-1 provided extra processing features, and Super FX powered polygonal or other specialized visual effects. The chip associated with Alpha 2’s graphic decompression is S-DD1.