Explanation:
I want to say option B - Both forces can act without objects touching.
The type of energy that is produced by the system that is described is heat energy. The correct answer is D.
Gravity is the correct answer.
It would need to be over 20 because if the load of the Pulley E is 20 and the effort is 20, then they will be equal and the Pulley would not move, so your answer is at least 20