The answer is C, search for gold. I got right on the test, all my classmates because it was the easiest problem. I hope you're just extremely making sure if that the answer you chose is correct. This book is obviously about using dogs and searching for gold for if you've read it, which you probably did. The moderator removed the other answer because it wasn't informal enough (Warfare probably don't even know what you're talking about, I think they're preventing you from "tackling" this problem on your own.)