Which sentence would be MOST
important to include in an objective
summary of the article?

A
The acidification of the ocean is a tragic example of the negative
impact humans are having on the planet.

B. Human activity is much more impactful to carbon levels on the atmosphere than volcano eruptions are.

C
Calcium carbonate, the active ingredient in antacid, is mostly made by shell-building organisms

D.
The intricate carbon cycle is one of nature’s most powerful and beautiful phenomenons