$A$ non-conducting solid sphere of radius $R$ has a uniform volume charge density $\rho$. The electric potential at the center of the sphere is related to the potential at the surface and outside the sphere due to this uniform charge distribution.
Statement-$1$: When a charge $q$ is moved from the surface to the center of the sphere,the change in its potential energy is $q\rho R^2 / 6\varepsilon_0$.
Statement-$2$: The electric field at a distance $r$ $(r < R)$ from the center of the sphere is $\rho r / 3\varepsilon_0$.

• A
  Statement-$1$ is true,Statement-$2$ is true,and Statement-$2$ is the correct explanation for Statement-$1$.
• B
  Statement-$1$ is true,Statement-$2$ is true,and Statement-$2$ is not the correct explanation for Statement-$1$.
• C
  Statement-$1$ is true,Statement-$2$ is false.
• D
  Statement-$1$ is false,Statement-$2$ is true.