Answer:
B. 500
Explanation:
the scale only measures increments of 1,000 pounds, e.g. its scale is 0 pounds, 1,000 pounds, 2,000 pounds, 3,000 pounds, etc.
What happens if something weighs exactly 1,500 pounds (or 500, 2500, 3500, etc)? The scale will measure either 1,000 or 2,000 pounds, so the maximum margin of error is ± 500 pounds.