A Wire Is Bent into the Shape of a Circle

A wire is bent into the shape of a circle of radius r = 0.10 m and carries a 20.0-A current in the direction shown.
-What is the magnitude of the magnetic field at the center of the loop?

A) 2.0 × 10^-5 T
B) 1.3 × 10^-5 T
C) 2.0 × 10^-4 T
D) 1.3 × 10^-4 T
E) zero tesla