Corbin Company had 100,000 shares of common stock outstanding. Options to purchase 5,000 shares of common stock were outstanding at the beginning of the year. The options can be exercised to purchase stock at $50 per share. The average market price of the stock was $80. The net increase in the dilutive earnings per share denominator is:

a. 25,000shares

b. 5,000 shares

c. 3,125 shares

d. 1,875 shares