Choice "B" is correct. Contingent shares (that are dilutive) are included in the calculation of basic earnings per share (EPS) if (and as of the date) all conditions for issuance are met. Stock options do not enter into the calculation of basic EPS.
Choices "a" and "d" are incorrect, because stock options do not enter into the calculation of the basic EPS, but will enter into the calculation of dilutive EPS if dilutive (i.e., the average market price of the common stock during the period exceeds the exercise price of the option).
Choice "c" is incorrect. If contingent shares are dilutive (on EPS) and meet conditions for issuance, they would enter into the calculation of basic EPS.
