Researchers have found that the DNA in bacteria deteriorates sharply after about 1.1 million years, ----.
A) whereas the DNA of the average bacterium has about 3 million units
B) which consisted of just 210 units linked together
C) after which the size of the DNA gets cut in half
D) but older microorganisms didn’t perform as well
E) and some of the oldest microorganisms were watched for as long as a year