A boy runs on a horizontal road with a speed of $4 \mathrm{m} {\mathrm{s}}^{-1}$ while it is raining. He sees that the rain is making an angle $\mathrm{\theta }$ with the vertical while running from west to east. However, when he runs from east to west, the angle is $\mathrm{\alpha }$. The rain is pouring down at an angle $45°$ with the vertical and at a speed of $8 \mathrm{m} {\mathrm{s}}^{-1}$ as shown in the figure. The ratio $\frac{\tan \theta }{\tan \alpha }$ is,

• A

  $(1-\sqrt{2}{)}^2$
• Correct answer
  B

  $(1+\sqrt{2}{)}^2$
• C

  $(1+\sqrt{2})$
• D

  $(\sqrt{2}-1)$

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