Giant Molecular Clouds,which Are Major Sites of Star Formation,can Be

Giant molecular clouds,which are major sites of star formation,can be up to:

A) 10 times the size of the solar system and contain 2 to 3 solar masses of material.
B) 10 pc across and contain a few thousand solar masses of material.
C) 100 pc across and contain 2 million solar masses of material.
D) 1000 pc across and contain 100 million solar masses of material.