Consider Two Current-Carrying Circular Loops

Multiple Choice

Consider two current-carrying circular loops.Both are made from one strand of wire and both carry the same current,but one has twice the radius of the other.If the magnetic field strength at the center of the smaller loop is B,what is the magnetic field strength at the center of the larger loop?

A) 8B
B) 4B
C) 2B
D) B/2
E) B/4