When Studying an Ancient Ecosystem's Organisms,what Was the Advantage of Looking

When studying an ancient ecosystem's organisms,what was the advantage of looking for DNA samples in permafrost?

A) The freezing temperature preserves the DNA.
B) Areas with permafrost are older than other parts of the world, allowing scientists to collect samples back 1.5 to 2 million years.
C) The enzymes that make DNA are still active in the cells.
D) It is easier to take solid core samples.
E) Most plants and animals evolved in Siberia.