A portfolio consisting of a $5-$year par yield corporate bond that provides a yield of $15\%$ and a long position in a $5-$year CDS costing $100$ basis points per year is $($approximately$)$ a long position in a riskless instrument paying $12\%$ per year. What are arbitrage opportunities in this situation is risk$-$free rate is $10\mathrm{.}5\%?$ What if it is $14\mathrm{.}5\%?$