Please solve this question in details and explaination. Thanks so much in advance.

The figure below shows a cross section of a long cylindrical conductor of radius a = 4.10 cm containing a long cylindrical hole of radius b = 1.64 cm. The central axes of the cylinder and hole are parallel and are distance d = 2.04 cm apart; current i = 5.25 A is uniformly distributed over the tinted area. (a) What is the magnitude of the magnetic field at the center of the hole? (b) What is the magnitude if b = 0? (c) What is the magnitude if d = 0? (a) Number i Units V (b) Number Units (c) Number i Units