What Is True of the Web of Causation? Select All

What is true of the web of causation? Select all that apply.

A) It is understood that the web may be sufficiently altered by an attack at one link that may render prevention efforts less effective.
B) The web of causation can be defined such that the effect may be the result of a complex interaction of causes, with the understanding that not every effect is the result of a single cause.
C) An important principle of epidemiology is that for effective public health interventions to be carried out, they require a complete understanding of the web of causation.
D) It is possible that additional unexpected side effects may occur, thus obscuring the relationships within the web of causation.