When calculating diluted earnings per share, the correct approach regarding dilutive share options is as follows:

A. The number of shares that will be issued at the exercise price when the options are exercised are used in the calculation of the denominator for diluted earnings per share, considering the dilution effect they have.

This aligns with the principle outlined in the reference text, which states that for dilutive share options, the number of shares to be added to the denominator for the diluted earnings per share calculation is determined by a formula that takes into account the exercise price and the average market price of ordinary shares. The numerator, in this context, typically remains unchanged, reflecting the idea that dilutive instruments do not adjust the profit or loss amount but affect the number of shares used in the calculation.

Therefore, the correct answer is:

B. The number of shares that will be issued at the exercise price when the options are exercised are the shares that must be used as the denominator for the diluted earnings per share calculation.