Maren received 10 NQOs (each option gives her the right to purchase 12 shares of stock for $9 per share) at the time she started working when the stock price was $8 per share. When the share price was $14 per share, she exercised all of her options. Eighteen months later she sold all of the shares for $23 per share. What is the amount of Maren's bargain element?

0

600

720

1680

none of these choices are correct