In an office desks were made for average height but both shorter and taller employees felt pain. What is the main error?

Correct answer: Ignoring real user diversity

Direct answer: A, ignoring real user diversity. Ergonomic design must consider the range of people who will use a product, not just one average measurement. A desk fixed at the average height may be too high for a shorter worker and too low for a taller worker, forcing awkward shoulder, elbow, wrist or back positions. The practical solution may include adjustable furniture or a design based on appropriate user-size ranges. A is correct because the error is treating a diverse group as if everyone had the same body dimensions. B is irrelevant: colour does not explain posture-related pain. C does not identify a furniture-fit problem. D concerns naming, not physical comfort or safety. Memory cue: average is a statistic, not automatically a suitable setting for every person.