In recent years, cats have become the biggest threat to wildlife in country A. These cats (including pet cats and stray cats, wild cats, farm cats and other owner cats) kill and kill animals by tens of billions a year. Some animal charities have suggested that cats Collars with bells. Cats with collars have a hunting success rate that is at least one-third lower than other cats, and the number of kills will be greatly reduced. Which of the following, if true, would best challenge the proposal? ['when the cat is hunting, it does not take into account the sound of the bell.', 'this move will lead to a cat food chain break, which could lead to massive cat deaths in the country.', 'there is data showing that the number of wild animals who have died of vehicle crushing in recent years has increased sharply.', 'it ’s difficult to put a collar on the “owner cat”, and most of the animals are killed by the “owner cat”.']