Which Statement About Purines and Pyrimidines Is True

Which statement about purines and pyrimidines is true?

A) Purines include the bases of cytosine and thymine;pyrimidines include the bases of adenine and guanine.
B) Pyrimidines are found in RNA,whereas purines are found in DNA.
C) Purines consist of hydrogen,carbon,oxygen,and nitrogen,whereas pyrimidines have phosphorus,hydrogen,carbon,oxygen,and nitrogen.
D) Purines have only single bonds in their structure,whereas pyrimidines have both single and double bonds.
E) Purines are double-ring structures,whereas pyrimidines are single-ring structures.