The articulation of vertebrae in the vertebral column occurs when:

• A
  Post-zygapophyses of a vertebra in front fit beneath the pre-zygapophyses of the vertebra behind.
• B
  Post-zygapophyses of a vertebra in front fit over the pre-zygapophyses of the vertebra behind.
• C
  Pre-zygapophyses of a vertebra fit over the post-zygapophyses of the vertebra in front.
• D
  Pre-zygapophyses and post-zygapophyses of vertebrae simply touch one another.