Company A shares are currently trading at 15$ each. The following table shows the possible payoffs from the shares next year.

State of the world	Dividend	Stock Price
Good economy	0$	12$
Bad economy	2.60$	16$

If the two scenarios are equally likely, what is the standard deviation of Company A's stock returns?

a. -20% b. 21% c. 2% d. 22% e. 47%