A sphere of radius R carries charge density \[\rho \]proportional to the square of the distance from the center such that \[\rho =C{{R}^{2}}\], where C is a positive constant. At a distance R/2 from the center, the magnitude of the electric field is

• A. \[\frac{C{{R}^{3}}}{20{{\in }_{0}}}\]
• B. \[\frac{C{{R}^{3}}}{10{{\in }_{0}}}\]
• C. \[\frac{C{{R}^{3}}}{5{{\in }_{0}}}\]
• D. \[\frac{C{{R}^{3}}}{40{{\in }_{0}}}\]