Two adjacent sides of a triangle are represented by the vectors $2 \bar{i}+\bar{j}-2 \bar{k}$ and $2 \sqrt{3} \bar{i}-2 \sqrt{3} \bar{j}+\sqrt{3} \bar{k}$. Then the least angle of the triangle and perimeter of the triangle are respectively

• A

  $\frac{\pi}{3} ; 3(3+\sqrt{3})$
• B

  $\frac{\pi}{12} ; 6+3 \sqrt{2}$
• C

  $\frac{\pi}{2} ; 12$
• Correct answer
  D

  $\frac{\pi}{6} ; 9+3 \sqrt{3}$

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