If the vector function $\overrightarrow{F}=\widehat{a_x}(3y-k_1z)+\widehat{a_y}(k_2x-2z)-\widehat{a_z}(k_3y+z)$ is irrotational, then the values of the constants $k_1$,$k_2$ and $k_3$, respectively, are

- $0.3, -2.5, 0.5$
- $0.0, 3.0, 2.0$
- $0.3, 0.33, 0.5$
- $4.0, 3.0, 2.0$