A coaxial cable consists of a thin inner conductor fixed along the axis of a hollow outer conductor. The two conductor carry equal currents in opposite directions. Let `B_1 and B_2` be the magnetic fields in the region between the conductors and outside the conductor, respectively. Then,
A. `B_(1)!=0, B_(2)!=0`
B. `B_(1)=B_(2)=0`
C. `B_(1)!=0,B_(2)=0`
D. `B_(1)=0,B_(2)!=0`
