The electric field is $\mathbf{E}(z, t) = E_0 [\cos(kz - \omega t)\hat{i} + \sin(kz - \omega t)\hat{j}]$. Which statements is/are TRUE?
(A)
The wave is circularly polarized
(B)
The wave propagates in the $+z$ direction
(C)
The magnitude $|\mathbf{E}|$ is constant
(D)
The wave is linearly polarized