The Radius of a Coil of Wire with N Turns

The radius of a coil of wire with N turns is r = 0.28 m. A clockwise current of I_coil = 1.0 A flows in the coil, as shown. A long, straight wire carrying a current I_wire = 29 A toward the left is located 0.04 m from the edge of the coil. The magnetic field at the center of the coil is zero tesla. Determine N, the number of turns.

A) 8
B) 2
C) 6
D) 4
E) 1