Two Variables Are Uncorrelated in All of the Cases Below $|{}^{\sigma } X Y | \leq \sqrt { \sigma _ { x } ^ { 2 } \sigma _ { y } ^ { 2 } }$

Multiple Choice

Two variables are uncorrelated in all of the cases below, with the exception of

A) being independent.
B) having a zero covariance.
C) $|{}^{\sigma } X Y | \leq \sqrt { \sigma _ { x } ^ { 2 } \sigma _ { y } ^ { 2 } }$
D) E(Y $\mid X$ ) = 0.