steady current carrying wire form magnetic field lines in form
of concentric circles around the current carrying wire having
centres on , current carrying wire. Direction of magnetic field
line at any point is given by Maxwell right hand screw rule, at any
point. If you have doubt why a current carrying conductor produces
magnetic field than you should know charge at rest has only
electric field ,but charge in uniform motion have both electric and
magnetic field. current is rate of flow of charge that's why a
current carrying conductor produces magnetic field around it
Christian Orested discovered first magnetic effect of electric
current. So don't think for option D ,correct one is B.