If the electrostatic potential were given by \[\phi ={{\phi }_{0}}({{x}^{2}}+{{y}^{2}}+{{z}^{2}}),\]where is constant, then the charge density giving rise to the above potential would be.

• A. 0
• B. \[-6{{\phi }_{0}}{{\varepsilon }_{0}}\]
• C. \[-2{{\phi }_{0}}{{\varepsilon }_{0}}\]
• D. \[-\frac{6{{\phi }_{0}}}{{{\varepsilon }_{0}}}\]