In a quadrilateral the angles are in the ratio 3:4:5:6. Then the difference between the greatest and the smallest angle is

• A.  \[\angle DAC={{54}^{o}}\]                      
• B.  \[\angle ACB={{63}^{o}}\]
• C.  \[\angle BAC\]                    
• D.  \[{{72}^{o}}\]