JEE Main 2023 Physics question on Magnetism and Moving Charges

A single current carrying loop of wire carrying current I flowing in anticlockwise direction seen from +ve z direction and lying in xy plane is shown in figure. The plot of $j$ component of magnetic field (By) at a distance '$a$' (less than radius of the coil) and on yz plane vs z coordinate looks like

1. A.
   By (0, a, z) [graph showing a single positive peak]
2. B.
   By (0, a, z) [graph showing two positive peaks with a dip in between]
3. C.
   By (0, a, z) [graph showing one negative peak followed by one positive peak]
4. D.
   By (0, a, z) [graph showing a sinusoidal-like wave with negative then positive excursion]

[JEE Main 2023 · 29 Jan · Shift 1]