Let \( \vec{a} = 3\hat{i} - \hat{j} + 2\hat{k} \), \( \vec{b} = \vec{a} \times (\hat{i} - 2\hat{k}) \) and \( \vec{c} = \vec{b} \times \hat{k} \). Then the projection of \( \vec{c} - 2\hat{j} \) on \( \vec{a} \) is:
\( 2\sqrt{7} \)
\( 2\sqrt{14} \)
\( \sqrt{14} \)
\( 3\sqrt{7} \)