Which of the Following Is Not True About Document Type

Multiple Choice

Which of the following is not true about document type declarations for XML documents?

A) They are not required.
B) They are required for type-valid documents.
C) They cannot be contained inside the XML document.
D) Storing the DTD externally allows many documents to be validated against the same DTD.
E) The DTD can be extended by the developer with any elements he or she wants to include.