The electric field of an electomagnetic wave propagating in the positive $z$-direction is given by $$ \left.\text{E}=\hat{a_x} \sin (\omega t-\beta z\right)+\hat{a_y} \sin \left(\omega t-\beta z+\frac{\pi}{2}\right) $$ The wave is
- linearly polarized in the $z$-direction
- elliptically polarized
- left-hand circularly polarized
- right-hand circularly polarized