$$ \text { The two structures written below represent } $$

• A

  pair of diastereomers
• B

  pair of enantiomers
• Correct answer
  C

  same molecule
• D

  both are optically inactive

Solution

Hints:
I \& II are same Fischer projection because $180^{\circ}$ rotation doesn't change configuration

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