For what value of $\lambda$ are the vectors $\lambda \hat{i}+(1+\lambda) \hat{j}+(1+2 \lambda) \hat{k}$ and $(1-\lambda) \hat{i}+\lambda \hat{j}+2 \hat{k}$ perpendicular?

• Correct answer
  A

  $-\frac{1}{3}$
• B

  $\frac{1}{3}$
• C

  $\frac{2}{3}$
• D

  1

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