Answer:
A
Explanation:
Process of elemenation also its kinda the only relevent one....
 
        
                    
             
        
        
        
Organic  means it is made only of carbon.
Explanation:
The all four types of macromolecule are organic means these all four type of macromolecule made up of carbon. These four macro molecules are carbohydrate, protein, nucleic acid and Proteins.  All are essential cell component perform a wide array of function. 
Biological macromolecule is organic so they contain carbon. A part of carbon they contain nitrogen, hydrogen and additional minor element.   Enzymes and some hormone are example of protein. 
 
        
             
        
        
        
The correct answer is B. Thymus gland: enables immature lymphocytes to mature into T cells
        
                    
             
        
        
        
Equilibrium: Equilibrium is a state in which opposing forces or influences are balanced.
Hope this helps :)