Question

read the passage.
saving the rhinos
poachers in africa are killing large numbers of rhinos for their horns. rhinoceros horns, valued for use in traditional medicines in vietnam and china, can fetch as much as thirty-six thousand dollars a pound. officials have tried to protect the rhinos: they have created fenced areas for the animals, patrolled their habitats, and even tried removing their horns. despite these efforts, the number of rhinos in africa has been dwindling. one creative solution to the poaching problem is to remove the rhinos from africa altogether. ray dearlove, the founder of the australian rhino project, came up with a plan to relocate eighty rhinos to a safari park outside adelaide, australia, where a breeding herd can be established.
what is the main, or central, idea of the passage?
because other attempts to protect african rhinos from poachers have failed, the australian rhino project is relocating the rhinos to australia.
officials have tried to protect african rhinos from poachers by guarding their habitats and removing their horns, but their efforts have been largely unsuccessful.

Explanation:

The passage first outlines the threat of poaching to African rhinos, details failed protection efforts, then introduces the Australian Rhino Project's relocation plan as a new solution. The first option encompasses the full scope of the passage: the failure of prior protections and the new relocation solution, while the second only covers the failed efforts, not the central proposed solution.

Answer:

Because other attempts to protect African rhinos from poachers have failed, the Australian Rhino Project is relocating the rhinos to Australia.