The value of \({\cos ^{ - 1}}\left( {\cos \frac{{5\pi }}{3}} \right) + {\sin ^{ - 1}}\left( {\sin \frac{{5\pi }}{3}} \right)\) is

• A. \(\frac{\pi }{2}\)
• B. \(\frac{{5\pi }}{3}\)
• C. \(\frac{{10\pi }}{3}\)
• D. 0