After $15$ years of contributions of $$3,500$ at the end of every six months to a Retirement Savings Plan, the accumulated amount stood at $$232,536.$ What semiannually compounded nominal rate of return was earned by the funds in the RSP$?2\mathrm{.}5\%10\mathrm{.}0\%$O $12\mathrm{.}5\%5\mathrm{.}0\%7\mathrm{.}5\%$