Which statement regarding Section $401($k$)$ plans is CORRECT?

Question $1$ options:

a$)$

The maximum pretax elective deferral for a participant age $35$ is $$22,500$ in $2023.$

b$)$

Employer contributions and their accrued earnings are always immediately $100\%$ vested in the plan.

c$)$

A Section $401($k$)$ plan is a nonqualified profit$-$sharing or stock bonus plan.

d$)$

Elective deferrals in a cash or deferred arrangement $($CODA$)$ are not subject to FICA and FUTA taxes.