Which of the following is true about the actions of a formocresol pulpotomy?

A. Formocresol pulpotomies do not produce dentinal bridging.
B. Formocresol pulpotomies contain four zones of fixation.
C. Formocresol pulpotomies are initiated when the inflammation has spread into the tissues within the root canal.
D. All of the above are true.