The correct answer should be A. Bob twists his back to pick up the materials to feed his press machine.
This is unsafe and can lead to work injury, while the remaining two show that the workers have found a way to prevent injuries, which is why A is the correct answer.
A. Bob twists his back to pick up the materials to feed his press machine.
Explanation:
Ergonomic is the proper use of the mechanics of the body, in this case bob shouldn´t be twisting his back to pick up the materials he should be turning around with his whole body, this can put undesired pressure on his lower back and waist and can eventually lead to damage in the tissue, nerves and muscles.
