The Standard Error Of $\bar { x } _ { 1 }$

Multiple Choice

The standard error of $\bar { x } _ { 1 }$ - $\bar { x } _ { 2 }$ is the

A) pooled estimator of $\bar { x } _ { 1 }$ - $\bar { x } _ { 2 }$ .
B) variance of the sampling distribution of $\bar { x } _ { 1 }$ - $\bar { x } _ { 2 }$ .
C) standard deviation of the sampling distribution of $$\bar { x } _ { 1 }$$ - $\bar { x } _ { 2 }$ .
D) margin of error of $\bar { x } _ { 1 }$ - $\bar { x } _ { 2 }$ .