Hi LSAT99.9,
Thanks for your question! To "ensure" is to make certain that (something) shall occur or be the case. For instance, if stopping at the red light ensures that you'll avoid getting into an accident, the proper diagram would be as follows:
- Stop at red light No accident
Likewise, if I tell you, "We must ensure that a sane person is elected president," the following diagram would seem appropriate:
- Elect president Sane
Essentially, whatever is being "ensured" or "guaranteed" to occur is the necessary condition. Of course, not all uses of the verb would entail conditional reasoning, so make sure to consider the context in which the verb is being used.
Hope this helps!
Thanks,