Your Research Assistant Finds a Positive Relationship Between Mother's Education

Multiple Choice

Your research assistant finds a positive relationship between mother's education and income at age 40.The relationship remained after controlling for the family's social class.This means that

A) social class is really the causal variable.
B) social class does not have an impact on the relationship.
C) the original relationship is spurious.
D) income is caused by neither the mother's education level nor her social class.
E) the mother's education has no effect on her future income.