Which of these gymnosperms are known to be important in maintaining the balance of carbon in an ecosystem?
a. garden flowering plants
b. ferns and liverworts
c. mosses and horsetails
d. redwood tree forests

D. redwood tree forests

Redwood forests can be significant reservoir for fixing atmospheric carbon dioxide. Through photosynthesis the redwood tree captures the atmospheric carbon and convert it into glucose as an energy reservoir for trees. Also, the soil organic matter of redwood forests is the accumulation of dead plant material, partially decayed or completely decayed plant and animal matter fixes carbon in the form of decomposed matter. This decomposed matter is again absorbed by plants. Hence, maintains the balance of carbon in the ecosystem.

i am pretty sure the answer is c

a. the production of carbon dioxide through the process of photosynthesis