Consider a $4\%$ coupon, $$1000$ par value, and $15$ years in maturity, and is sold for $$1000.$ It is callable after $7$ years. The bond is a convertible bond allowing the investor to exchange the bond for $40$ shares of common stock in the future. The current stock price is $$20.$ The stock has a dividend yield of $2\%$ and growth of $5\%$ per year. If you need the current rate of interest, it is $6\%.$

If the company decides to call back the bond, and give you $$1040,$ what would you do$?$ Take $$1040,$ or convert the bond? Show your calculations to prove your answer.