Suppose you have $$10,000$ in cash and you decide to borrow another $$10,000$ at a$($n$)7\%$ interest rate to invest in the stock market. You invest the entire $$20,000$ in an exchange $-$ traded fund $($ETF$)$ with a $10\%$ expected return and a $20\%$ volatility. The expected return on your of your investment is closest to

A$.7\mathrm{.}6\%$

B$.9\mathrm{.}9\%$

C$.8\%$

D$.5\%$