Find the angle between the vectors $\hat i - 2\hat j + 3\hat k$ and $3\hat i - 2\hat j + \hat k$

Question

$\begin{array}{1 1} (A) \cos^{-1} \bigg( \large\frac{2}{7} \bigg) \\ (B) \cos^{-1} \bigg( \large\frac{4}{7} \bigg) \\ (C) \cos^{-1} \bigg( \large\frac{1}{7} \bigg) \\ (D) \cos^{-1} \bigg( \large\frac{5}{7} \bigg) \end{array}$