Harry, an age $45$ participant in his employer's simplified employee pension, resigned to take a new job and received a $$20,000$ complete distribution from his designated Roth account in the plan. All his contributions and the contributions of his employer$-$a total of $$12,000-$were allocated to the Roth account. How much of the distribution, if any, must Harry include in his income?

A$)$ No Roth account distribution is includible in income

B$)$ $$8,000$

C$)$ $$12,000$

D$)$ $$20,000$