Cho phương trình sinx = sin alpha. Chọn kết luận đúng

A. $\left\{\begin{array}{l}x=\alpha +k\pi \\ x=\pi -\alpha +k\pi \end{array}\right.\left(k\in Z\right)$

B. $\left\{\begin{array}{l}x=\alpha +k2\pi \\ x=\pi -\alpha +k2\pi \end{array}\right.\left(k\in Z\right)$

C. $\left\{\begin{array}{l}x=\alpha +k2\pi \\ x=-\alpha +k2\pi \end{array}\right.\left(k\in Z\right)$

D. $\left\{\begin{array}{l}x=\alpha +k\pi \\ x=-\alpha +k\pi \end{array}\right.\left(k\in Z\right)$