default or selected kernelversion does not have config value CONFIG_OPROFILE_EVENT_MULTIPLEX.
Result is shown for kernelversion 6.9.5

OProfile multiplexing support (EXPERIMENTAL)

configname: CONFIG_OPROFILE_EVENT_MULTIPLEX

Linux Kernel Configuration
└─>General architecture-dependent options
└─>OProfile multiplexing support (EXPERIMENTAL)
In linux kernel since version 2.6.32 (release Date: 2009-12-02)  
The number of hardware counters is limited. The multiplexing
feature enables OProfile to gather more events than counters
are provided by the hardware. This is realized by switching
between events at a user specified time interval.

If unsure, say N.