Verbal Aptitude

Data shows that fields where earthworm counts are highest produce superior maize yields. The agronomist concludes that adding earthworms alone will turn barren clay into productive soil. What causal error is committed?

Options:

• (A) Overlooking that high organic matter causes both high earthworm populations and high soil fertility (common cause).
• (B) Ignoring that maize requires sunlight.
• (C) Assuming that earthworms eat maize roots.
• (D) Believing that earthworms live in soil.