A Researcher Noticed That, for Streams Along the East Coast

Multiple Choice

A researcher noticed that, for streams along the East Coast, the amount of money spent on restoration and the number of distinct fish populations present appeared to have a negative correlation.
Which of the following statements is most likely to be the reasoning the researcher used to decide that a lurking variable must be present?

A) The data would be wrong without this variable, because correlations cannot be negative.
B) The researcher expected a positive correlation, so obviously something must be wrong.
C) More money spent on restoration likely indicates a stream of lesser quality; hence, there may be fewer fish present.
D) None of these answers is correct.