Sandwick Corporation was organized on January 1, 2010, with authorized capital of 500,000 shares of $10 par value common stock. During 2010, Sandwick issued 20,000 shares at $12 per share, purchased 2,000 shares of treasury stock at $13 per share, and sold 2,000 shares of treasury stock at $14 per share. What is the amount of additional paid-in capital at December 31, 2010?
a) $42,000
b) $0
c) $2,000
d) $40,000