c
(c) Let sphere has uniform chare density \(\rho \,\left( { = \frac{{3Q}}{{4\pi {R^3}}}} \right)\) and \(E\) is the electric field at distance \(x\) from the centre of the sphere.
Applying Gauss law
\(E.\,4\pi \,{x^2} = \frac{q}{{{\varepsilon _0}}} = \frac{{\rho V'}}{{{\varepsilon _0}}} = \frac{\rho }{{{\varepsilon _0}}} \times \frac{4}{3}\pi {x^3}\)
(\(V' = \) Volume of dotted sphere)
 \(E = \frac{\rho }{{3{\varepsilon _0}}}x\) \(==>\) \(E \propto \,x\)