For what value of $m$ are the vectors $2 \hat{i}-3 \hat{j}+4 \hat{k}$, $\hat{i}+2 \hat{j}-\hat{k}$ and $m \hat{i}-\hat{j}+2 \hat{k}$ coplanar?

• A

  $0$
• B

  $5 / 3$
• C

  $1$
• Correct answer
  D

  $8 / 5$

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