The Graph Below Shows the Normal Concentration of Morphogens a and B

Multiple Choice

The graph below shows the normal concentration of morphogens A and B throughout a Drosophila embryo.

If morphogen B is injected into the head end of an embryo,the embryo is likely to develop

A) normally.
B) a second tail at the head end.
C) a second head at the tail end.
D) two heads at the head end.