I believe the Answer would be B because they are both increasing but I am not 100% correct
        
             
        
        
        
I think it would be the thrid
        
             
        
        
        
Letter M is in between L and N. So like this LMN and o is in between N and P. So like this NOP. So technically the difference from o to m is just one of N.
 
        
             
        
        
        
Ggbb = gray hair and red eyes
ggBB = white hair and black eyes
GgBb = gray hair and Black eyes
ggbb = white hair and red eyes