If a consolidated return is required for the taxable year, which of the following is most accurate?

A. Any amounts paid or assessed, whether correctly or incorrectly based on separate returns, will be credited to the payment of the consolidated tax.

B. Computing the tax liability of the group on a consolidated basis is optional if separate returns were filed for the year.

C. If the income of a corporation that was not a member of the group is included in the consolidated return, the consolidated return will be considered as including only the income of the actual members of the group.

D. The tax liability of the group must be computed on a consolidated basis if there has been a failure to include the income of one or more subsidiaries.