Here is the OE as below:
The greater the population density the greater the chance a gorilla is infected. Koluga gorillas have a greater population density than Morgania gorillas, therefore one would expect them to be more . Based on captured gorillas, the Morgania gorillas are more likely to be infected.
The paradox can best be resolved by (D). If scientists are far more likely to capture non-infected than infected Kogula gorillas, than that accounts for the difference in results.
(A) would be correct if the passage mentioned that researchers only captured the gorillas in the plains, and uninfected Koluga gorillas are more likely to venture out of their natural habitat.
(B)does not differentiate between the two gorillas so it unlikely to help resolve the discrepancy.
(C) is similar but different. It is not the total number of captured Kogulas that is important. ‘Twice as likely’ is based on rate not total number.
(E) is out of scope.
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