The correct answer is the ocean carbon cycle.
The United States Joint Global Ocean Flux Study was aimed at understanding the ocean carbon cycle.
In the late 1980s, the United States launched the Joint Global Ocean Flux Study to learn more about the concentrations and fluxes of carbon in the oceans. The United States National Science Foundation and the National Oceanic and Atmospheric Administration supported the study. Biogeochemistry was created as a new research field to know more about the measurements of carbon in the ocean. The study ended in 2005.
The other options of the question were: b) the ocean phosphorus cycle, c) global warming, d) fish breeding patterns.
