If employee speed increased after workplace improvement but fatigue did not reduce, what should be checked?

Correct answer: Whether the new layout is creating hidden body strain

Ergonomics evaluates the fit between people, tasks, tools, and the workplace. A faster output rate does not prove that the design is healthy, because workers may be using awkward postures, excessive force, repetitive motions, or poorly placed equipment. Thus A is correct: hidden physical strain and other fatigue indicators should be assessed. B wrongly treats speed as the only outcome, while C and D do not provide valid evaluation methods.