(A) Visitors have not spent as much time studying the behavior of big cats as the zookeepers have.
Does not provide any new information to strengthen the argument. Rather states the same information as mentioned in the passage. Eliminate option.
(B) Those who would be most interested in opportunities to assist in feeding big cats are already regular visitors and would not bring along new visitors.
The argument is more concerned with the safety of the visitors rather than bringing in new visitors. Eliminate option.
(C) Burglars who are attacked by an occupant during a home invasion usually incur serious injuries requiring emergency treatment. Out of scope. Eliminate option.
(D) People who visit zoos have less experience interacting with wild animals than do people who do not visit zoos.
We do not know how experienced either of these people are so we cannot arrive at a conclusion. Eliminate option.
(E) Feeding big cats requires entering their habitat, which can only be done safely after previous interaction with the animals. This shows that due to no previous attraction for visitors they are under more danger and hence strengthens the argument. Correct option.