Answer: D. Derek assumed the risk of a bear attack by joining the tour group, so he cannot hold the tour company liable
Explanation:
Derek has to accept that by joining the tour group, he assumed some the risk of some elements of danger amongst them the bear attack.
Even though there had been no prior attack by bears in the mountain, a mountain hike still has some inherent danger in it and this includes bears. He cannot hold the tour company liable using this reason alone.