Thomas owns a closely held partnership interest that currently represents 60% of the value of his adjusted gross estate (one-half of the closely held business value is real estate). Thomas is concerned about paying sizable estate taxes at his death, so he is considering the inter vivos transfer of part of the partnership interest to his son. If Thomas decides to make the transfer, his partnership interest will be reduced to 30% of his adjusted gross estate. His will bequeaths $30,000 cash to his favorite qualified charity, the business interest to his son, and leaves the rest of the estate to his wife. A disadvantage for Thomas of transferring the business interest, while he is alive, to his son is that the estate will no longer qualify for which of the following?

A) A Section 303 stock redemption

B) The marital deduction for property given to his spouse

C) The alternate valuation date

D) Section 6166 installment payment of estate taxes