The angle between two vectors given by \[6\bar{i}+6\bar{j}-3\bar{k}\] and \[7\overline{i}+4\overline{j}+4\overline{k}\] is [EAMCET (Engg.) 1999]

• A.                 \[{{\cos }^{-1}}\left( \frac{1}{\sqrt{3}} \right)\]
• B.                             \[{{\cos }^{-1}}\left( \frac{5}{\sqrt{3}} \right)\]
• C.                 \[{{\sin }^{-1}}\left( \frac{2}{\sqrt{3}} \right)\]  
• D.                 \[{{\sin }^{-1}}\left( \frac{\sqrt{5}}{3} \right)\]