Final answer:
To qualify for the charitable deduction for estate taxes, the donation must be made to a qualified charity. A donation to a U.S. charity qualifies for the deduction.
Step-by-step explanation:
To qualify for the charitable deduction for estate taxes, the donation must be made to a qualified charity and meet certain requirements. Option a is incorrect because the donation must be made by the decedent's estate, not the executor. Option b is correct because a donation to a U.S. charity qualifies for the charitable deduction for estate taxes. Option c is incorrect because donations to foreign charities do not qualify for the charitable deduction for estate taxes. Therefore, the correct answer is option b: A donation to a U.S. charity.