Figure showns four solid spheres, each with charge Q uniformly distributed through its volume. The figure also shows a point P for each sphere. All at the same distance from the centre of the sphere. Rank the spheres according to the magnitude of the electric field they produce at point P.
A. ` I and II" tie " to III to IV`
B. `II to III to IV`
C. `III to II to I to IV`
D. all tie
