If a line $\overline {AB}$ makes angle $45^{\circ}$ with positive $x-axis$ and $120^{\circ}$ with positive $y-axis$, then the angle $\theta$ made by the line with positive $z-axis$ is ?

Question

$(a)\;30^{0}\qquad(b)\;45^{0}\qquad(c)\;60^{0}\qquad(d)\;75^{0}$