A solid non-conducting sphere of radius R carries a charge Q distributed uniformly throughout its volume. At a radius r (r < R) from the center of the sphere the electric field has a value E. If the same charge Q were distributed uniformly throughout a sphere of radius 2R the magnitude of the electric field at a radius r would be equal to:

Hence the answer is E inside .

Explanation:  

E inside  

so if r1 will be the same then  

E   proportional to 1/R3  

so if R become 2R  

E becomes 1/8 of the initial electric field.

The electric field is E/8.

Explanation:

The electric field due to a solid sphere of uniform charge density inside it is given by

where, is the volume charge density and r is the distance from the center.

For case I:

So, electric field at a distance r is

Case II:

So, the electric field at a distance r is

where are the vectors ?