The Poynting vector of an electromagnetic wave in vacuum is\(S = \left\{ {\left( {120W/{m^2}} \right){{\sin }^2}\left[ {8.0rad/m} \right)z + \left( {2.4 \times {{10}^9}rad/s} \right)t]} \right\}k\)What is the frequency of the wave?

• A. 382 MHz
• B. 172 MHz
• C. 241 MHz
• D. 54.6 MHz