Tessellate S.T.E.M.S - Physics - College - Set 3 - Problem 3

Given the Stern-Gerlach apparatus as given below, how must the angle $\theta$ of the SGn device be oriented so as to maximize the number of particles that are transmitted by the final SGz device?

where SGn device means the Stern-Gerlach device with the magnetic field oriented along the $\hat{n}$ direction where the axis $\hat{n}$ makes an angle $\theta$ in the x-z plane with respect to the z-axis

This problem is a part of Tessellate S.T.E.M.S.