On June $30,2023,$ a company purchases a $10-$year bond with a par value of $$50$ million. $5\%$ interest payments are due semiannually. The company designates the bond as held$-$to$-$maturity. The market rate of interest is $10\%.$

On December $31,2023$ the company estimates the fair$-$value of the bond to be $$36$ million.

On December $31,2024$ the company estimates the fair$-$value of the bond to be $$38$ million.

On December $31,2025$ the company estimates the fair$-$value of the bond to be $$40$ million.

On January $1,2026,$ the company sells the bond for $$42$ million. What is the gain on the sale? Round to the nearest tenth of a decimal.

Group of answer choices

$$2$ million

$$5\mathrm{.}5$ million

$$5$ million

$$4\mathrm{.}4$ million

$$7\mathrm{.}6$ million