After Controlling for Z, a Researcher Finds Evidence of a Spurious

Multiple Choice

After controlling for Z, a researcher finds evidence of a spurious relationship between X and Y. What step should be taken next?

A) Z should become the new independent variable.
B) Z should become the new dependent variable.
C) Z should be disregarded and a new control variable should be selected.
D) Z should be disregarded and a new independent variable should be selected.