In Factor Analysis, a Factor Is

In factor analysis, a factor is

A) the variable that best correlates with all the other variables entered into the factor analysis.
B) the set of variables, among all those measured, that best correlates with the criterion variable.
C) a mathematical expression of the common variance in all the variables entered into the factor analysis.
D) a mathematical expression of the common element in a subset of variables that were entered into the factor analysis and that are correlated with each other.