Which of the following statements is$/$are correct regarding SEP contributions made by an employer $($assume the employee did not make a Roth election$)?$

$1.$ Contributions are subject to FICA and FUTA.

$2.$ Contributions are currently excludable from employee$-$participant$$s gross income.

$3.$ Contributions are capped at $$22,500$ for $2023.$

a$.1$ only.

b$.2$ only.

c$.1$ and $2.$

d$.1,2,$ and $3.$

Please fully explain your answer.