Aileen sold 500 shares of Kim Inc. that is a qualified small business stock. The sales price was $12,500 and Aileen's basis was $10,000 (assume no selling costs). Aileen held this stock for 61 months. How is the gain treated for determining Aileen's tax?

a. $2,500 gain; 15% gain

b. $2,500; short-term gain

c. $-0-

d. $1,250; 28% gain