So we know that to transport materials in or out of the cell, we need to have access to both the inside and outside of the cell. This would require that the protein be a transmembrane protein that reaches both the inside and the outside of the cell.
So in this case, let's look at pore proteins. These are proteins that cross a membrane and act as a pore for the materials that need to cross the membrane.
One example of a pore protein is an aquaporin. These proteins aid in the transport of water into or out of a cell.
Therefore, the answer to your question is: A) Pore proteins.
 
        
             
        
        
        
One of the possible effects of increased carbon dioxide concentration on our planet would be a warmer climate.
<h3>Greenhouse effect</h3>
Carbon dioxide is one of the numerous greenhouse gases that exist in nature. The gases are responsible for the warming of the planet.
Carbon dioxide and other greenhouse gases form a blanket layer in the atmosphere and trap some of the reflected solar radiations from the sun, preventing them from escaping back to space.
The more the concentration of greenhouse gases in the atmosphere, the more the solar radiation that is trapped and the warmer the earth gets. 
More on greenhouse effects can be found here: brainly.com/question/13706708
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A: has a specific active site
        
             
        
        
        
decomposers break down dead things and waste, so I would say that dead animals would not go back into the ground as fast and the nutrients would not go back into the cycle