The Full Extent of the Diversity and Abundance of Life

The full extent of the diversity and abundance of life on earth has only been understood in the past few years as a result of

A) microscopy techniques to identify the vast quantity of viruses present in all environments.
B) advances in deep oceanography and deep earth mining engineering.
C) environmental movements to preserve parks, coral reefs, and glaciers.
D) techniques to identify organisms that do not rely on culturing.