The Avian Erythroblastosis Virus Contains an Oncogene Called ErbB That

The avian erythroblastosis virus contains an oncogene called erbB that encodes ___________.

A) an altered EGF receptor that is missing part of the extracellular domain that binds to the growth factor
B) an altered insulin receptor that binds insulin with lower affinity
C) an altered transcription factor that turns on hemoglobin synthesis
D) an elongated auxiliary protein of the cytoskeleton
E) an underexpressed nuclear protein