What is the magnetic field intensity vector vec$(H)$ between two parallel sheets with separation $\text{'}d$ along $z-$axis both sheets carrying surface current vec$(k)=k_y$vec$(a{)}_y?$

$[$ESE EC $2007]$

$($A$)-k_y$vec$(a{)}_y$

$($B$)+k_y$vec$(a{)}_y$

$($C$)-k_y$vec$(a{)}_x$

$($D$)$ zero