A Uniform Circular Ring Has Charge Q and Radius R

Multiple Choice

A uniform circular ring has charge Q and radius r.A uniformly charged disk also has charge Q and radius r.Calculate the electric field at a distance of r along the axis of the ring divided by the electric field at a distance of r along the axis of the disk.

A) 1.0
B) 0.60
C) 1.7
D) 0.50
E) 0.85