Why are the miller-urey experiments essential to the theory of evolution?

Ibelieve the answer is d. macula  hope my answer has you : )

If you're looking for an even spread of clay, silt and sand, add a considerable amount of sand and some clay until the 3 even out". soil texture triangle. silty clay loam soil is approximately 20 percent or less sand, 25 to 40 percent clay, and 40 to 70 percent silt.

I’m not sure about this question