The angle between the lines \(\vec{r}=3 \hat{i}-2 \hat{j}+1 \hat{k}+\mu(4 \hat{i}+6 \hat{j}+12 \hat{k})\) and \(\overrightarrow{\mathrm{r}}=7 \hat{i}-3 \hat{j}+9 \hat{k}+\lambda(5 \hat{i}+8 \hat{j}-4 \hat{k})\) is:
1
\(\cos ^{-1} \frac{10}{7 \sqrt{105}}\)
2
\(\cos ^{-1} \frac{5}{72}\)
3
\(\cos ^{-1} \frac{2}{35}\)
4
\(\cos ^{-1} \frac{7}{98}\)