A、Moving all the cats to other parts of the world. B、Keeping cats inside 24 hours a day. C、Keeping ferocious animals to kill cat

If(13)New Zealand businessman Gareth Morgan has his druthers, it could all be over for fluffy pals:(13)The economist and environmental proponent wants to see his country rid of pets that pose a danger to native birds—namely cats. New Zealand plays home to an enormous array of native birds species, but(14)the island nation’s human inhabitants have the highest cat ownership rate in the world: 28% of households have one cat: another 20% have two or more. Since those cats are preying on the country’s native birds—in many cases to the point of extinction, says Morgan—one or the other has to go. "If you are reading this there is a good chance that you are a cat owner and you are probably upset at the thought of getting rid of your beloved pet," writes Morgan, urging readers to consider the relevant statistics. Like: New Zealand’s record cat ownership rates, as noted, but also that(14)cats have so far contributed to the extinction of nine native bird species, and presently threaten 33 more. Morgan is advocating that people take an informed approach to a serious problem. "We appreciate the fact that you have an emotional connection with your pet and that pet ownership is a rewarding experience... If you think NZ’s native species are precious and should be fostered then it’s important you be a responsible cat owner.(15)That means keep them inside 24 hours a day and if that’s impractical then when the time comes ensure this is the last cat you ever own."
13. What does Gareth Morgan do?
14. What do we know about cat ownership in New Zealand?
15. What measures does Morgan suggest to save birds from the danger posed by cats?