Which biogeochemical process is most impacted by burning fossil fuels?

Correct answer: B) Carbon cycle.
Burning fossil fuels, such as coal, oil, and natural gas, releases large amounts of carbon dioxide (CO2) into the atmosphere. This increased CO2 concentration in the atmosphere disrupts the natural balance of the carbon cycle, leading to a net increase in atmospheric CO2 levels.

The carbon cycle is the biogeochemical cycle that describes the movement of carbon through the Earth's ecosystems, including the atmosphere, biosphere, hydrosphere, and lithosphere. The burning of fossil fuels is a significant human-induced perturbation to the carbon cycle, as it introduces additional carbon that was previously stored in the Earth's crust into the active carbon cycle.