It Is Possible for a Will to Include Supplementary Documents

It is possible for a will to include supplementary documents, provided they have been properly incorporated into the will. Which of the following is not a condition of the doctrine of incorporation?

A) The incorporated document(-s) must be clearly identified in the will.
B) The incorporated document(s) must normally be in existence at the time of the will
C) The incorporated document(s) may be added by codicil if they are created after the will is exercised.
D) The incorporated document(s) can either be in existence at the time of the will or at least named in the will where it exists in the future.