To Be Nonlinear, in the Context of Systems Thinking, Means

To be nonlinear, in the context of systems thinking, means:

A) a particular set of events must always occur, but not in any particular order.
B) events can give rise to unpredicted events and have unforeseen ramifications.
C) when the distribution of system achievements is graphed over time, it seems completely random.
D) effect can sometimes precede cause, so it is often difficult to tell what came first.
E) butterflies flap their wings and ponds will ripple.