Biết \(\log 2 = a\) thì \(\log \sqrt[4]{{\frac{{32...

Câu hỏi: Biết \(\log 2 = a\) thì \(\log \sqrt[4]{{\frac{{32}}{5}}}\) bằng

A \(\frac{1}{4}\left( {{a^6} - 1} \right)\) .                              

B  \(\frac{1}{4}\left( {5a - 1} \right)\).                                          

C  \(\frac{1}{4}\left( {6a + 1} \right)\).                                   

D  \(\frac{1}{4}\left( {6a - 1} \right)\).