\(25{\sin ^2}x + 15\sin 2x + 9{\cos ^2}x = 25.\)
A.\(x = \frac{\pi }{2} + k\pi \), \(x = \arctan \frac{7}{{15}} + k\pi \left( {k \in Z} \right)\)
B.\(x = \frac{\pi }{2} + k\pi \), \(x = \arctan \frac{3}{5} + k\pi \left( {k \in Z} \right)\)
C.\(x = \frac{\pi }{2} + k\pi \), \(x = \arctan \frac{8}{{15}} + k\pi \left( {k \in Z} \right)\)
D.\(x = \frac{\pi }{2} + k\pi \), \(x = \arctan \frac{2}{5} + k\pi \left( {k \in Z} \right)\)

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