Which of the Following Determinations Does Not Require Knowing the Amounts

Which of the following determinations does not require knowing the amounts of one's U.S.­ versus foreign­source
Income?

A) Calculation of a U.S. person's total taxable income.
B) Calculation of U.S. withholding tax on the FDAP income of foreign persons.
C) Calculation of the foreign earned income exclusion.
D) Calculation of a foreign person's income effectively connected with carrying on a U.S. trade or business.