What amphibian embryonic tissue was shown by Spemann and Mangold to induce the formation of the neural plate, and in some cases, to induce a complete second embryo.

A.	equatorial mesoderm
B.	dorsal lip of the blastopore Spemann and Magold found that the dorsal lip of the blastopore is responsible for neural induction. That is, this tissue has the ability to direct the development of host tissue to form a second neural tube.
C.	yellow crescent
D.	optic cup
E.	zone of polarizing activity