Let $P_1: x+y+z=1, P_2: 2 x+y+z=3$ be two planes, and let $L$ denote the line of intersection of $P_1$ and $P_2$. Let $P$ be the plane passing through the point $(1,2,1)$, and normal to $L$. Which of the following equations represents $P$ ?

• A

  $x+2 y+z=6$
• Correct answer
  B

  $y-z=1$
• C

  $x+y+2 z=5$
• D

  $x+z=2$

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