The Major Axes of Development in Early Fruit-Fly Embryos Are

The major axes of development in early fruit-fly embryos are established as a result of initial differences in the distribution of specific mRNAs and proteins encoded by genes in the female parent (genetic maternal effect) . These differences in distribution establish concentration gradients of morphogens, which cause different genes to be activated in different parts of the embryo.
-High concentration of which protein stimulates the development of anterior structures?

A) Dorsal
B) Toll
C) Bicoid
D) Nanos