default or selected kernelversion does not have config value CONFIG_SECURITY_SECLVL.
Result is shown for kernelversion 5.4.123

BSD Secure Levels

modulename: seclvl.ko

configname: CONFIG_SECURITY_SECLVL

Linux Kernel Configuration
└─>Security options
└─>BSD Secure Levels
In linux kernel since version 2.6.12  
Implements BSD Secure Levels as an LSM. See
Documentation/seclvl.txt for instructions on how to use this
module.

If you are unsure how to answer this question, answer N.

source code: