Maybe something like crystal I think, but out of yours I would pick karma!
Explanation:
Using blocks of layered geometric tone and color, feininger creates the illution that the image is receding the backward, with the idea that the tone and color create light in the background, using semi-transparent layers this creates a different intensity of color, which gives this illusion.
The Mound Builders used metal tools, and were probably metal builders. Based on that information I would say the answer is B.Copper, because copper is a metal.
I'd have to go with A. The rhino picture. The image is composed of what looks like notches or "gouges" used by a sharp tool, which removes certain areas by gouging them out with the tool and then leaving the actual print on the top of the surface. Often, a sort of paint roller would be passed over the surface image. The gouged out portions would not be pressed by the roller. Very cool and were used in many printing presses when they used templates.
