Six years ago, HOPCO granted Lin Sing an incentive stock option to purchase 1,000 shares of HOPCO stock at $55 per share. On date of grant, the market price was $50 per share. This year, Lin Sing exercised the option when the market price was $73 per share. How much ordinary income does Lin Sing recognize because of the exercise? $0 $5,000 $9000 $18,000