In which of the following spheres of Earth is most carbon stored long-term?

a - Atmosphere

b-Biosphere

c - Cryosphere

d - Geosphere

Carbon is the fourth most abundant element. It is the building block of life on Earth. The Geosphere is the sphere of Earth in which the most carbon stored long-term Answer: D

The Geosphere carbon cycle operates at very long, slow time scales of thousands to millions of years.