Structural Equation Modeling (A Type of Model-Testing Research) Uses Large

Structural equation modeling (a type of model-testing research) uses large samples. What is the reason for this?

A) Interactions among many variables are tested.
B) The research is experimental, so a large, multi-site sample is preferred.
C) Causation cannot be demonstrated in a small sample.
D) Differences often are minuscule, because the sample is homogeneous, and so the effect size is small.