What was the result of Helen Elizabeth Shearburn Clark's study published in Nature?

A. Description of a new species of fish found in New Zealand's rivers
B. Identification of a new type of coral reef off the coast of New Zealand
C. Discovery of a new species of echinoderm found in New Zealand's forests
D. Proposal of a new class of echinoderms, Xyloplax medmiformis, based on sunken timber samples
Answer: 