Answer: Fierce Grizzly Attacks Innocent Bystanders.
This is the only option that contains an unnecessary and biased opinion. By phrasing the headline in this way, the author gives the grizzly bear a negative intention, while framing the attacked people as "innocent." This encourages a negative view of the bear which is unlikely to be accurate. Therefore, this is the best example of an opinion, as the author is letting his personal views affect the way he tells the news.