c
Consider $2$ circles with radii $A \& 2 A$ and particles moving on them with constant angular velocity $\omega$
Choose $x$ axis to be horizontal on which the projection of the particles are to be taken.
When the projection of the first particle is at a distance $A / \sqrt{2}$ from origin, it is at an angle $45^{0}$ in the first quadrant.
whereas the second particle is at an angle $180^{0}$.
i.e the phase difference is $135^{0}$
