default or selected kernelversion does not have config value CONFIG_AEDSP16_MSS.
Result is shown for kernelversion 5.6.17

MSS emulation

configname: CONFIG_AEDSP16_MSS

Audio Excel DSP 16
└─> MSS emulation

Answer Y if you want your audio card to emulate Microsoft Sound
System. You should then say Y to "Microsoft Sound System support"
and say N to "Audio Excel DSP 16 (SBPro emulation)".