The electric field for a plane electromagnetic wave travelling in the positive z-direction is represented by which one of the following?

$\hat{k} E_0e^{i(kz - ωt + \phi)}$ $\hat{i} E_0e^{i(kx - ωt + \phi)}$ $\hat{i} E_0e^{i(kz + ωt + \phi)}$ $\hat{k} E_0e^{i(kz + ωt + \phi)}$

$\hat{i} E_0e^{i(kx - ωt + \phi)}$

Since EM Wave is travelling along Z -direction hence electric field will be either along X- or Y- Direction.