Why is it important to know the background and projected extinction rates for global species?

It is important to know the background and projected extinction rates for global species because more species are becoming threatened in well-populated and developed countries. Biological extinction is the complete disappearance of a species from the earth. Background extinction rate is the rate that existed before modern humans evolved some 200,000 years ago. The extinction rates have risen in some areas as human populations have spread over most of the globe. 

It attracts a metal striker, which then hits the bell. i think D is the correct answer.