Please elaborate more on your question so I can help you
Is there supposed to be an image if so there is none
A pump jack scaffold must be fitted with two positive gripping mechanisms to prevent slippage. Pump jacks are a uniquely designed scaffold consisting of a platform supported by movable brackets on vertical poles. The brackets are designed to be raised and lowered in a manner similar to an automobile jack. It is important to make sure that pump jack brackets have two positive gripping mechanisms to prevent any failure or slippage.
The correct answer is D: which is none of the above.
Hint: a wreckling ball contains pontential energy that acts like a pendulum
a pot of water contains pontential thermal energy
