Local visitors to nature reserves in South Africa often complain that

Local visitors to nature reserves in South Africa often complain that foreign tourists on guided tours, despite their inexperience and lack of knowledge, manage to see rare animals more often than they do. Unlike in a zoo, the animals wander around to their hearts' content in a huge natural area, and there is never any guarantee that a visitor to such a reserve will see a specific type of animal. Although it is believed that the success of the foreign tourists is a result of "beginner's luck", what could actually explain this phenomenon is the fact that __________.

Which of the following best completes the passage below?

(A) the numbers of animals in the various nature reserves have increased in recent years due to adequate rains

(B) there is no communication between foreign tourists and local visitors to the park

(C) the tours offered to foreign tourists are guided by people with more experience than the average local visitor

(D) rarely seen animals are usually those that are either nocturnal or vulnerable to attacks by predators

(E) the foreign tourists take courses in their own countries prior to the tours, and thereby gain extra knowledge for the efficient classification of animals