In a coaxial straight cable, the central conductor and the outer conductor carry equal currents in opposite directions. The magnetic field is zero

Question

$\begin {array} {1 1} (a)\;Outside\: the\: cable & \quad (b)\;In\: between\: the\: two\: conductors \\ (c)\;Inside\: the\: inner \: conductor & \quad (d)\;Inside\: the\: outer\: conductor \end {array}$