在 △ABC\bigtriangleup {ABC}△ABC 中, (a+c)(sinA−sinC)=b(sinA−sinB)\left( {a + c}\right) \left( {\sin A - \sin C}\right) = b\left( {\sin A - \sin B}\right)(a+c)(sinA−sinC)=b(sinA−sinB) ,则 ∠C=\angle C =∠C= ( )A. π6\frac{\pi }{6}6π B. π3\frac{\pi }{3}3π C. 2π3\frac{2\pi }{3}32π D. 5π6\frac{5\pi }{6}65π