Dr$.$ Kang is a self$-$employed physician who has net earned income of $$150,000.$ She would like to make the maximum allowed contribution to her self$-$employed pension plan

$($SEP$).$ How much is Dr$.$ Kang's contribution?

a$.$ $$37,500$

b$.$ $$30,000$

C$.$ $$20,000$

d$.$ $$66,000$