A long container has a square base of side $L$. The height to which water should be filled so that the force on one of its side surface is the same as that at its bottom is (ignore atmospheric pressure)

• A

  $L / 4$
• B

  $L$
• C

  $L / 2$
• Correct answer
  D

  $2 L$

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