In Which Region of the Hertzsprung-Russell Diagram Does a Newly

In which region of the Hertzsprung-Russell diagram does a newly formed protostar first appear when it begins to shine at visible wavelengths?

A) bottom right corner; very low luminosity because it is both small and cool
B) center of the main sequence since all protostars begin their lives at this position and move up or down the diagram, depending on their mass as time passes
C) right side; relatively large luminosity because of its size but cool temperature
D) top left corner; at the top of the main sequence, down which it will progress with time