Answer:
Carbon based molecules have 3 main structures which are 
straight chain
branched chains
rings
Explanation:
The structure or shape of carbon can be a straight chain, branched chained or in the form of rings. Examples of straight chain carbon includes propane, butane and pentane. Examples of branched chain carbons include members of the alkyl group like methyl and ethyl. Ring shaped carbons form structures in the form of rings like benzene which forms a six carbon ring. All these structures are made and dependent on the ability of carbon molecules to form four covalent bonds. Enormous, complex molecules can be formed by the binding of carbon chains to carbon rings. The carbon based molecules are very important as they are the basic buiilding blocks of life. Many important molecule like the DNA, RNA, lipids are made up of carbon atoms. 
 
        
             
        
        
        
Explanation:
In the process of photosynthesis, plants that contain chlorophyll utilize carbon dioxide and water using energy from sunlight that is absorbed by chlorophyll to make glucose + oxygen.
 
        
                    
             
        
        
        
The immune system<span> is made up of a chain of cells, tissues, and organs that work together to protect the body. </span>
        
                    
             
        
        
        
I think it’s gonna be b or c