A biologist used the Internet to contact scientists around the world to obtain information about declining amphibian populations. He was able to gather data on 936 populations of amphibians, consisting of 157 species from 37 countries. Results showed that the overall numbers of amphibians dropped 15% a year from 1960 to 1966 and continued to decline about 2% a year through 1997. What is the importance of collecting an extensive amount of data such as this?
A. Researchers will now be certain that the decline in the amphibian populations is due to pesticides.
B. The data collected will prove that all animal populations around the world are threatened.
C. Results from all parts of the world will be found to be identical.
D. The quantity of data will lead to a better understanding of the extent of the problem.