Giải phương trình \({\cos ^2}x - 3\sin x + 3 = 0\).
A.\(x = \dfrac{\pi }{2} + k\pi \,\,\left( {k \in \mathbb{Z}} \right)\).
B.\(x = \dfrac{\pi }{2} + k2\pi \,\,\left( {k \in \mathbb{Z}} \right)\).
C.\(x = \dfrac{\pi }{4} + k2\pi \,\,\left( {k \in \mathbb{Z}} \right)\).
D.\(x = \dfrac{\pi }{4} + k\pi \,\,\left( {k \in \mathbb{Z}} \right)\).