This Year Nathan Transferred $2 Million to an Irrevocable Trust

This year Nathan transferred $2 million to an irrevocable trust established for the benefit of his nephew. The trustee is directed to accumulate income for the next 5 years before distributing the trust corpus to Nathan's nephew. In past years Nathan has made taxable gifts of $6 million and used a unified credit on an exemption equivalent of $5 million. What amount of gift tax, if any, must Nathan remit?

A) $620,000
B) $400,000
C) $345,450
D) zero - there is a $10.9 million exemption equivalent
E) None of these