Which of the following statements about species extinction is correct?

• A. Current rates of species extinction appear to be 100 to 1000 times higher than historical rates of extinction.
• B. The history of life has been punctuated by five mass extinction events, with 75 to more than 90 percent of all species disappearing in a geological blink of an eye in catastrophes.
• C. The major threats to species extinction fall into four broad categories: habitat loss or degradation, the introduction of nonnative species, overexploitation, and pollution effects.
• D. All of the above.

Answer: (D)