One Cannot Assume That the Problems Observed in Children Have

One cannot assume that the problems observed in children have been "caused" by a specific form of maltreatment because:

A) Children living in psychologically abusive homes often experience additional risk factors.
B) Data obtained from direct observational studies must by necessity be limited to small groups.
C) Even the newest statistical techniques have come no closer to pinpointing causality.
D) Experts are most interested in understanding the combined effects of specific maltreatments.