Suppose you are a stock investor in firm A$.$ Your financial advisor just told you that the firm's Market$/$Book ratio was $2.$ You find out the firm's total common stock equity is $$4,000,000$ and the firm has $1,000,000$ common stock shares outstanding. What was the stock price of firm A when your finanical advisor calculated the Market$/$Book ratio?

A$.$ Not enough information

B$.$ $$8$

C$.$ $$2$

D$.$ $$4$