Find the curvature \( K \) of the curve given below. \[ \mathbf{r}(t)=\mathrm{i}+2 t^{2} \mathrm{j}+2 t \mathrm{k} \] \( \frac{5}{\sqrt{\left(5+16 t^{2}\right)^{3}}} \) \( \sqrt[4]{\frac{5}{\left(5+16