<u>Answer:</u> C. A plant absorbing carbon dioxide during photosynthesis
<em>A plant absorbing carbon dioxide during photosynthesis can be considered as assimilation in the carbon cycle.
</em>
<u>Explanation:</u>
<em>The process of carbon fixation is called assimilation in carbon cycle. In the atmosphere carbon occurs in the form of carbon dioxide. </em>
By the process of carbon fixation this carbon dioxide is converted into carbon compounds and these act as source of energy in an ecosystem.
Photosynthesis is an example of carbon fixation process. Other processes like chemo-synthesis also fix carbon. <em>Majority of carbon fixation takes place in marine environments. </em>
decreasing the availability of natural fuels
