TQ$9$ micks full retirement age is $66.$ If his primary insurance amount is $$2,000$ at full retirement, what would it be if he delayed recieving it until he was $68$ years and $2$ months old?

a$.$ $$2,346\mathrm{.}67$

b$.$ $$2,160\mathrm{.}00$

c$.$ $$2,320\mathrm{.}00$

d$.$ $$2,363\mathrm{.}83$