The graph above shows the progress of a chemical reaction. Based on the graph, which of the following is true?
 Reaction A is enzyme-catalyzed, while reaction B is not enzyme-catalyzed.
 Reaction A is not enzyme-catalyzed, while reaction B is enzyme-catalyzed.
 Reaction A uses cofactors, while reaction B does not use cofactors.
 Reaction A and reaction B use cofactors.
                                             
                                          
                                          
                                        
											 
					                  