If the magnetic field in a plane progressive wave is represented by the equation $\mathrm{B}_{\mathrm{y}}=2 \times 10^{-7} \sin \left(0.5 \times 10^3 x+1.5 \pi \times 10^{11} \mathrm{t}\right) \mathrm{T}$, then the frequency of the wave is (In the equation time t is in second)

• Correct answer
  A

  $75 \times 10^9 \mathrm{~Hz}$
• B

  $150 \times 10^9 \mathrm{~Hz}$
• C

  $75 \times 10^7 \mathrm{~Hz}$
• D

  $150 \times 10^7 \mathrm{~Hz}$

Hence, the correct answer is option: 'A'.