What Is the Relationship Between a First-Order and a Zero-Order

Multiple Choice

What is the relationship between a first-order and a zero-order correlation?

A) The first-order correlation is based on the zero-order correlation but modifies the original bivariate association to account for a third variable.
B) The first-order correlation is the bivariate correlation between X₁ and Y, and the zero-order correlation is the bivariate correlation between X₁ and X₂.
C) The first-order correlation is the bivariate correlation between X₁ and X₂, and the zero-order correlation is the bivariate correlation between X₂ and Y.
D) Both are synonyms for the same thing.