In a quadrilateral ABCD, If AO and BO are the bisectors of \[\angle \mathbf{A}\] and \[\angle B\] respectively \[\angle \mathbf{C}=\mathbf{3}{{\mathbf{0}}^{{}^\circ }}\]and\[\angle \mathbf{D}=\mathbf{7}{{\mathbf{0}}^{{}^\circ }}\]. Then, \[\angle \mathbf{AOB}=\]?

• A.  \[{{40}^{{}^\circ }}\]                       
• B.  \[{{50}^{{}^\circ }}\]
• C.  \[{{80}^{{}^\circ }}\]                                   
• D.  \[{{100}^{{}^\circ }}\]