The elements constituting a will may not always be clear when the will is written on more than one piece of paper. When one document is treated as the will and another is referred to and included therein although it was not formally executed with the will,

A$.$ The doctrine of integration is applied.

B$.$ An act of independent significance has occurred.

C$.$ The second document is incorporated by reference.

D$.$ The second document is treated as a codicil.