In January 2007, Castro Corporation, a newly formed company, issued 10,000 shares of its $10 par common stock for $15 per share. On July 1, 2007, Castro Corporation reacquired 1,000 shares of its outstanding stock for $12 per share. The acquisition of these treasury shares:
a. decreased total stockholders' equity.
b. increased total stockholders' equity.
c. did not change total stockholders' equity.
d. decreased the number of issued shares.