$\frac{\mathrm{q}}{\mathrm{m}}=\frac{2 \pi \mathrm{v} \cos \theta}{\mathrm{B}}=\mathrm{constant} \Rightarrow\left(\frac{\mathrm{e}}{\mathrm{m}}\right)_{1}+\left(\frac{\mathrm{e}}{\mathrm{m}}\right)_{2}=0$
Note Consider $e$ in place of $\mathrm{q}$ in solution.


$(A)$ $\vec{B}(x, y)$ is perpendicular to the $x y$-plane at any point in the plane
$(B)$ $|\vec{B}(x, y)|$ depends on $x$ and $y$ only through the radial distance $r=\sqrt{x^2+y^2}$
$(C)$ $|\vec{B}(x, y)|$ is non-zero at all points for $r$
$(D)$ $\vec{B}(x, y)$ points normally outward from the $x y$-plane for all the points between the two loops