CONFIG_ARCH_ARC is not available for thedefaultarchitecture x86.
Result is shown for architecture arm26
default or selected kernelversion does not have config value CONFIG_ARCH_ARC.
Result is shown for kernelversion 5.4.123

Archimedes

configname: CONFIG_ARCH_ARC

Linux Kernel Configuration
└─>System Type
└─>Archimedes
In linux kernel since version 2.6.12  
Say Y to support the Acorn Archimedes.

The Acorn Archimedes was an personal computer based on an 8MHz ARM2
processor, released in 1987. It supported up to 16MB of RAM in
later models and floppy, harddisc, ethernet etc.