The expected average rate of return for a proposed investment of $$614,400$ in a fixed asset with a useful life of $4$ years, straight$-$line depreciation, no residual value, and an expected total income of $$168,160$ for the $4$ years is $($round to two decimal places$)$

a$.13\mathrm{.}68\%$

b$.0\mathrm{.}55\%$

c$.6\mathrm{.}84\%$

d$.0\mathrm{.}27\%$