Suppose that Symantec is a small firm that has developed​ anti-virus computer software. Symantec currently earns ​$3 million per year in profits from selling its software. Dell informs Symantec that it is considering installing the software on every new computer it sells. Dell currently earns profits of​ $30 million but expects to sell more computers at a higher price if it can install​ Symantec software. Dell first chooses whether to offer Symantec​ $30 or​ $20 for each copy of its​ software, and then Symantec responds by either accepting or rejecting the offer. The strategies and corresponding profits​ (in millions) for Dell​ (D) and Symantec​ (S) are depicted in the decision tree to the right. What is the Nash equilibrium of the​ game