World commodity prices over the past 170 years have

A) steadily decreased in both the short run and long run.
B) decreased in the long run despite occasional short-run increases.
C) remained constant in the long run despite occasional short-run fluctuations.
D) steadily increased in both the short run and long run.

World commodity prices have shown a trend of decreasing in the long run, although there can be periods of short-run increases due to various factors such as supply disruptions, increased demand, or geopolitical tensions. This trend is attributed to technological advancements, improvements in production methods, and increased efficiency, which tend to lower the cost of production over time.