"We noticed the CAMPING club had set up their tents nearby" This is the answer because in the other sentences it is being used solely as a verb. Where as in the first sentence it is being used as a noun for the the club.
Answer: B) He is a very experienced hunter.
Explanation: In the given excerpt from "The Most Dangerous Game" we can see that Rainford is describing what happened in the scene of the hunting, even though he was not there. He describes all the steps the hunter followed, and he explains the reasons behind them, this indicates us that Rainford is a very experienced hunter, so the correct answer is the corresponding to option B.