C. Dilutive potential ordinary shares shall be determined independently for each period presented.

According to the relevant accounting standards, the number of dilutive potential ordinary shares, such as convertible securities, warrants, share options, and contingently issuable shares, should be determined independently for each period presented. This means that the calculation of dilutive potential ordinary shares and their impact on diluted earnings per share should be assessed separately for each reporting period. The calculation takes into account the specific conditions and potential effects of these instruments on the respective periods. Therefore, the correct answer is that dilutive potential ordinary shares should be considered individually for each period presented, implying that the calculation of the number of shares for diluted earnings per share is done separately for each financial reporting period, considering the dilutive impact of potential ordinary shares as if they were converted, exercised, or issued at the beginning of the period (for previously issued potential ordinary shares) or the date of issuance (for those issued during the current period).