The two planes $a x+b y+c z+d=0$ and $a x+b y+c z+d_1=0$, where $d \neq d_1$, have

• A

  one point only in common
• B

  three points in common
• C

  infinite points in common
• Correct answer
  D

  no points in common

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