. A steady current I flows along an infinitely long hollow cylindrical conductor of radius

A steady current I flows along an infinitely long hollow cylindrical conductor of radius R. This cylinder is placed coaxially inside an infinite solenoid of radius 2R. The solenoid has n turns per unit length and carries a steady current I. Consider a point P at a distance r from the common axis. The correct statement(s) is (are)

(a) In the region 0 < r < R, the magnetic field is non-zero

(b) In the region R < r < 2R,the magnetic field is alog the common axis

(c) In the region R < r < 2R,the magnetic field is tangential to the circle of radius r, centered on the axis

(d) In the region r > 2R, the magnetic field is non-zero