This author's attitude inference question is easy if you have the scale.
(C) gives you the author on the right side of the scale: concerned about the way regulations happen only after major pollution occurs.
The wrong answers:
(A) has the author on the right side of the scale. Cynical seems like a bit of a degree of opinion issue. But the bigger issue is the author doesn't think the problem is that we need international concern (although it does sometimes happen; see line 63). The problem is that the environmental damage has to happen first. This is what the author means by hindsight.
(B) has the other on the wrong side of the scale. The author is worried, not satisfied.
(D) is unsupported. Although the author seems concerned about pollution, there's no indication she is optimistic. In fact, judging by recent events (the 4th paragraph), there is little reason for optimism.
(E) is contradicted. The 4th paragraph makes clear the problem is lack of information. The author is not confident about this at all.
Feel free to post any questions about this problem.
Demetri