Consider an electromagnetic wave propagating in a vacuum. Choose the correct statement.

• A
  For an electromagnetic wave propagating in $+y$ direction,the electric field is $\vec{E} = \frac{1}{\sqrt{2}} E_{yz}(x, t) \hat{z}$ and the magnetic field is $\vec{B} = \frac{1}{\sqrt{2}} B_z(x, t) \hat{y}$.
• B
  For an electromagnetic wave propagating in $+y$ direction,the electric field is $\vec{E} = \frac{1}{\sqrt{2}} E_{yz}(x, t) \hat{y}$ and the magnetic field is $\vec{B} = \frac{1}{\sqrt{2}} B_{yz}(x, t) \hat{z}$.
• C
  For an electromagnetic wave propagating in $+x$ direction,the electric field is $\vec{E} = \frac{1}{\sqrt{2}} E_{yz}(y, z, t) (\hat{y} + \hat{z})$ and the magnetic field is $\vec{B} = \frac{1}{\sqrt{2}} B_{yz}(y, z, t) (\hat{y} + \hat{z})$.
• D
  For an electromagnetic wave propagating in $+x$ direction,the electric field is $\vec{E} = \frac{1}{\sqrt{2}} E_{yz}(x, t) (\hat{y} - \hat{z})$ and the magnetic field is $\vec{B} = \frac{1}{\sqrt{2}} B_{yz}(x, t) (\hat{y} + \hat{z})$.