In a birthday party, pizzas, burgers and cakes are served and it is represented by a Venn-diagram given below. Study the given diagram carefully and answer the following questions based on it. How many persons had cakes?

• A.  6                                
• B.  6 + 3         
• C.  6 + 4                          
• D.  6 + 2 + 3 + 4