If in $\triangle A B C, B=45^{\circ}, a=2(\sqrt{3}+1)$ and area of $\triangle A B C$ is $6+2 \sqrt{3}$ sq.units, then the side $\mathrm{b}=$

• A

  $8-4 \sqrt{3}$
• B

  $\sqrt{2}(\sqrt{3}+1)$
• C

  $4 \sqrt{2}$
• Correct answer
  D

  $4$

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