Malcolm wants to purchase an annuity that will pay him $$7,000$ at the end of every three months for $15$ years. His financial advisor has told Malcolm that this annuity will cost him $$250,000.$ What monthly compounded nominal interest rate was used in this calculation?

$18\mathrm{.}89\%$

$7\mathrm{.}51\%$

$9\mathrm{.}3\%$

$22\mathrm{.}67\%$

$12\mathrm{.}60\%$