Cho \(\sin a = \frac{{\sqrt 5 }}{3}\) . Tính \(\cos 2a\sin a\) 

A. \(\frac{{17\sqrt 5 }}{{27}}\)

B. \( - \frac{{\sqrt 5 }}{9}\)

C. \(\frac{{\sqrt 5 }}{{27}}\)

D. \( - \frac{{\sqrt 5 }}{{27}}\)