In an Experiment on an Early Frog Embryo, Cells from the Region

In an experiment on an early frog embryo, cells from the region that will eventually form the neural plate were transplanted to another part of the blastula. It was noticed that the transplanted tissue formed a second neural plate later in the embryo's development. The best explanation for this observation is that

A) the cells in the transplanted tissue had already differentiated.
B) cells surrounding the transplanted tissue at the new site influenced the tissue to differentiate.
C) biochemical activity within the transplanted cells had already determined which developmental genes would be activated.
D) the tissue underwent a transplant shock that caused it to differentiate.
E) all cells are committed to a specific terminal cell.