What Observation Made of Other Stars Seems to Suggest the Solar

Multiple Choice

What observation made of other stars seems to suggest the solar nebula theory is correct

A) Stars are found to exist more often in binaries than by themselves.
B) Protostars are seen to radiate much of their light at infrared wavelengths.
C) Nearby stars tend to be low-mass red dwarfs.
D) Young stars are found to have hot disks that surround them.