For Three Variables, X₁, X₂, and X₃, the Bivariate Correlation

Multiple Choice

For three variables, X₁, X₂, and X₃, the bivariate correlation coefficients are:
R₁₂ = 0.7; r₁₃ = 0; r₂₃ = 0.
The correlation of X₁ and X₂ controlling for X3 will be

A) stronger than the bivariate correlation r₁₂.
B) weaker than the bivariate correlation r₁₂.
C) the same as the bivariate correlation r₁₂.
D) uncertain.