The answer is d: all of the above! Hope this help!
        
             
        
        
        
Homologous
 
The fins of fishes and flipper of a whale are homologous structures since they have different structure but similar structure
 
        
                    
             
        
        
        
C does not correctly match
        
             
        
        
        
Answer; 
C. it is the part f the atom with the greatest mass
Explanation;
The nucleus of an atom is a small dense region at the center of an atom that contains protons and neutrons. 
Almost all the mass of an atom is located in the nucleus, with a very small contribution from the electron shells.
The protons are positively charged which gives the nucleus a positive charge while the neutrons have no charge.