PLEASE HELP FAST!!!! Which could be the first in solving the equation represented by the model below?
Which one? 
A. Add 4 positive unit tiles to each side 
B. Remove 4 unit tiles from each side 
C. Add 6 positive unit tiles to each side 
D. Remove 6 unit tiles from each side 
                                             
                                          
                                          
                                        
											 
			                   
					                  