On January 1, a company had outstanding incentive stock options exercisable to purchase 1,620 of its common shares for $15 each. The price of the company's common stock averaged $27 her share during the year and closed at $28 on December 31. When calculating diluted earnings per share for the year, application of the treasury stock method results in: (Click to select) a net increase in the denominator of 900 shares a net decrease in the denominator of 900 shares a net increase in the denominator of 720 shares a net decrease in the denominator of 720 shares