A conducting sphere of radius R has a charge Q on it. Which of the following graphs correctly represents the value of electric field E in the range $0 \le x < \infty$, where x is the distance of the point from the centre of the sphere ? (A) graph showing E constant for $x < R$ and decreasing for $x > R$ (B) graph showing E increasing linearly for $x < R$ and decreasing for $x > R$ (C) graph showing E zero for $x < R$ and decreasing for $x > R$ (D) graph showing E increasing to a peak at R and decreasing for $x > R$