Which of the Following Is the Denominator of the Earnings

Which of the following is the denominator of the earnings per share formula?

A) The denominator is the number of common shares outstanding at the end of the year.
B) The denominator is the average number of common shares outstanding for the year.
C) The denominator is the sum of the average number of common shares and the average number of preferred shares for the entire year.
D) The denominator is the sum of the number of common shares and the number of preferred shares outstanding at the end of the year.