Current density $(\frac{?}{\text{b}\text{a}\text{r}}(J)),$ in cylindrical coordinate system is given as

$J(r,,z),=0$ for $0$Ywhere vec$(I{)}_z$ is the unit vector along $z$ coordinate axis.

In the region, $(vec(H))\frac{J_0}{r^2-r^2}(r^2-a^3)\frac{J_0}{r^2}(r^3+a^3)\frac{J_0(r^3-a^3)}{3a^2}\frac{J_0}{2r}(r^3-a^3)a,$ what $is$ the expression for the magnitude $of6magnetic$ field intensity vector $(vec(H))?$

$(A)\frac{J_0}{r^2-r^2}(r^2-a^3)$

$(B)\frac{J_0}{r^2}(r^3+a^3)$

$(C)\frac{J_0(r^3-a^3)}{3a^2}$

$(D)\frac{J_0}{2r}(r^3-a^3)$