[Will Formalities] Mark Decided He Wanted a Will

[Will Formalities] Mark decided he wanted a will. Mark contacted Anthony, a reputable attorney with an expertise in estate planning. In their initial meeting, Mark described the property he owned and how he wished it to be distributed upon his death. Mark also specified his funeral arrangements. Anthony drew up the will and provided Mark with a draft. Mark made some minor revisions, which Anthony incorporated. Mark and Anthony went over the will one last time, in the presence of Anthony's administrative assistants, Stacy and Jason. Mark was satisfied with the will and signed it. Two years later, Mark wanted to revise his will to add his new wife, Karen. The document named Karen as the primary beneficiary instead of Mark's brother, John. Mark handwrote these provisions on a thin cutting board and labeled it "codicil," signed it, and attached it to his will. Mark unexpectedly dies and Karen and John dispute who should receive the majority of Mark's assets.
-What is the effect of Mark's codicil since it was written on a cutting board?

A) As long as it is handwritten, it is valid.
B) It is invalid because a codicil must be either electronic or on paper.
C) It is invalid because a codicil must be on paper.
D) It is invalid because a codicil must be electronic
E) It is valid because he attached it to the will.