If at the end of the period the nominal rate of return on your investment and the inflation rate turned out to be $10\%$ and $4\%,$ respectively, what was the real rate of return on your investment? a$.5\mathrm{.}77\%0$ b$.5\mathrm{.}66\%$ c$.4\mathrm{.}85\%0$ d$.9\mathrm{.}12\%0$ e$.6\mathrm{.}33\%$