In Many Animal Embryos,the Eye Develops Very Early

Multiple Choice

In many animal embryos,the eye develops very early.The Pax6 protein is important to eye development;its absence can prevent the formation of eyes in mice and humans.Thus,Pax6 probably acts as a(n) _____.

A) structural protein retinal and/or lens cells
B) intercellular signal transmitted between retinal and lens cells
C) transcriptional factor that regulates genes involving retinal and/or lens cells
D) extracellular matrix protein secreted by the retinal and/or lens cells