Final answer:
Martha and Lew should claim the foreign tax credit instead of the deduction, as it would provide a greater tax benefit given their 24 percent tax bracket.
Step-by-step explanation:
Martha and Lew need to decide between taking the foreign tax credit or claiming a deduction for foreign taxes paid on their Schedule A. Given that they are in the 24 percent tax bracket and itemize deductions, the better choice would usually be to claim the foreign tax credit. This is because a credit reduces their tax liability dollar-for-dollar, making it more valuable than a deduction which only reduces the amount of income subject to tax. Therefore, if they have enough foreign income to claim the full $400 as a credit, it would typically provide a greater tax benefit than a deduction.