If $\overrightarrow{a} = 3 \hat{i} - 2 \hat{j} + \hat{k}$ and $\overrightarrow{b} = \hat{i} + 2 \hat{j} + 5 \hat{k}$, then the unit vectors along $\overrightarrow{a} - \overrightarrow{b}$ is :

Question

( A ) $\frac{\sqrt{2\hat{i}+4\hat{j} + 4 \hat{k}} } {\sqrt{34}}$
( B ) $\frac{-2\hat{i}+4\hat{j} + 4 \hat{k} } {6}$
( C ) none of these
( D ) $\frac{\hat{i}-2\hat{j}-2 \hat{k} } {3}$