A U$.$S$.$ bank converted $$1$ million to Swiss francs to make a Swiss

franc loan to a valued corporate customer when the exchange rate

was $1\mathrm{.}35$ francs per dollar. The borrower agreed to repay the

principle plus $8\%$ interest in $1$ year. The borrower repaid Swiss

francs at loan maturity and when the loan was repaid the exchange

rate was $1\mathrm{.}40$ francs per dollar. What was the bank's dollar rate of

return? A$.4\mathrm{.}86$ percent B$.5\mathrm{.}58$ percent C$.5\mathrm{.}21$ percent D$.4\mathrm{.}14$

percent$$