Some statements are made about valva development in C. elegans.

A. C. elegans, an anchor cell, and a few hypodermal cells take part in the formation of the vulva.

B. If 3 of the hypodermal VPCs are killed by a laser beam, a normal vulva is still formed.

C. When the anchor cells as well as any of the six hypodermal cells are killed, the vulva will form.

D. If 3 of the hypodermal VPCs are killed by a laser beam, a normal vulva is not formed.

E. When the anchor cells as well as any of the six hypodermal cells were killed, the vulva did not form.

Select the correct combination of statements.