default or selected kernelversion does not have config value CONFIG_SCSI_MQ_DEFAULT.
Result is shown for kernelversion 6.9.9

SCSI: use blk-mq I/O path by default

configname: CONFIG_SCSI_MQ_DEFAULT

Linux Kernel Configuration
└─>Device Drivers
└─>SCSI device support
└─>SCSI: use blk-mq I/O path by default
In linux kernel since version 3.18 (release Date: 2014-12-07)  
This option enables the blk-mq based I/O path for SCSI devices by
default. With this option the scsi_mod.use_blk_mq module/boot
option defaults to Y, without it to N, but it can still be
overridden either way.

If unsure say Y.

depends
CONFIG_SCSI