When pigments are mixed together, more colors are being absorbed which results to few colors that will be reflected. Each pigment absorbs and reflects light which results to the "color" or hue that we see. When these pigments are to be mixed, then more wavelengths would be absorbed which results to lesser reflection.
I choose the option C.
N2 + 3H2 = 2NH3
Kingdom because there are 3 kingdoms - Eukarea, Prokarya and Archaea
