Tính \(\int {\left( {x - \sin 2x} \right)dx.} \)

A. \({x^2} + \frac{{\cos 2x}}{2} + C.\)

B. \(\frac{{{x^2}}}{2} + \frac{{\cos 2x}}{2} + C.\)

C. \(\frac{{{x^2}}}{2} + \cos 2x + C.\)

D. \(\frac{{{x^2}}}{2} + \sin x + C.\)