Which of the Following Was a Conclusion from the Experiments

Multiple Choice

Which of the following was a conclusion from the experiments of Spemann and Mangold?

A) Cytoplasmic determinants in the gray crescents are necessary for gastrulation.
B) In the late gastrula, regions of cells are already determined to form skin or nervous tissue.
C) In the early gastrula, regions of cells develop into tissues appropriate for their location.
D) The dorsal lip of the blastopore is the primary embryonic organizer.
E) The dorsal lip of the blastopore gives rise to grey crescent.