An electric field in free space is
$
\vec{E}=(2 x+5 y+6 z) \hat{\imath}+(5 x+4 y+10 z) \hat{\jmath}+(6 x+10 y+2 z) \hat{k} \mathrm{~V} / \mathrm{m}.$
The charge density is $\_\_\_\_$ $\mathrm{C} / \mathrm{m}^{3} .\left(\epsilon_{0}\right.$ is the permittivity of free space $)$
- $8 \epsilon_{0}$
- $10 \epsilon_{0}$
- $6 \epsilon_{0}$
- $4 \epsilon_{0}$
