The Orange Light of the Spectrum,and the Orange Produced by Mixing

The orange light of the spectrum,and the orange produced by mixing red and yellow spectral light:

A) can be distinguished from one another by brightness cues.
B) are made up of identical kinds of light waves.
C) can be distinguished because spectral orange is less muddy looking.
D) are indistinguishable from each other to the human color senses.