
Bruce F. answered 12/15/13
Tutor
4.8
(12)
Effective, gentle, fun. One of my students won award for most-improved
This is tricky because it is not well-written. For example, the US is not a system. I could go on.
Anyway, think about what the authors of the test are looking for. Sentence #2 uses "even though", which is not causal. Sentence #3 uses "because", which gives you a cause-and-effect relationship. Aha! This can be used to answer a "why" question. It's badly written and confusing, but that was apparently the author's intention.