$29.$ On January $1,2021,$ Stone Corporation's projected benefit obligation was $$20$ million. During $2021,$ pension benefits paid by the trustee were $$2$ million. Service cost for $2021$ is $$8$ million. Pension plan assets $($at fair value$)$ increased during $2021$ by $$4$ million as expected. At the end of $2021,$ there were no pension$-$related other comprehensive income $($OCI$)$ accounts. The actuary's discount rate was $10\%.$Determine the amount of the projected benefit obligation on December $31,2021.$O A$.$ $$82\mathrm{.}000\mathrm{.}000$O B$.$ $$30,000000$O C$.$ $$28\mathrm{.}000\mathrm{.}000$O D$.$ $$1,680,000$