$A$ carbon dioxide laser emits a sinusoidal electromagnetic wave that travels in a vacuum in the negative $x-$ direction. The wavelength is $10.6\,\mu m$ and the $\vec E$ field is parallel to the $z-$ axis,with $E_{max} = 1.5 \times 10^6\, V/m$. Then the vector equations for $\vec E$ and $\vec B$ as a function of time and position are:

• A
  $\vec E = \hat k [1.5 \times 10^6 \cos(8.93 \times 10^5 x + 3.78 \times 10^{14} t)]\, V/m$,$\vec B = \hat j [5.0 \times 10^{-3} \cos(8.93 \times 10^5 x + 3.78 \times 10^{14} t)]\, T$
• B
  $\vec E = \hat k [1.5 \times 10^6 \cos(8.93 \times 10^5 x + 3.78 \times 10^{14} t)]\, V/m$,$\vec B = -\hat j [5.0 \times 10^{-3} \cos(8.93 \times 10^5 x + 3.78 \times 10^{14} t)]\, T$
• C
  $\vec E = \hat k [1.5 \times 10^6 \cos(5.93 \times 10^5 x + 1.78 \times 10^{14} t)]\, V/m$,$\vec B = -\hat j [5.0 \times 10^{-3} \cos(5.93 \times 10^5 x + 1.78 \times 10^{14} t)]\, T$
• D
  $\vec E = \hat k [1.5 \times 10^6 \cos(5.93 \times 10^5 x + 1.78 \times 10^{14} t)]\, V/m$,$\vec B = \hat j [5.0 \times 10^{-3} \cos(5.93 \times 10^5 x + 1.78 \times 10^{14} t)]\, T$