A Wire of Thickness D = 5 Mm Is Tightly

A wire of thickness d = 5 mm is tightly wound 200 times around a cylindrical core to form a solenoid. A current I = 0.1 A is sent through the wire. What is the the magnetic field on the axis of the solenoid?

A) 6.6 × 10^-5 T
B) 2.5 × 10^-5 T
C) 1.3 × 10^-5 T
D) 3.6 × 10^-5 T
E) 9.8 × 10^-5 T