All of the Following Statements Concerning Nucleic Acids Are True

All of the following statements concerning nucleic acids are true EXCEPT:

A) Not all DNA is double stranded.
B) Nucleic acids have a linear "spine" composed of alternating sugars and bases.
C) Cytosine is found in all nucleic acid molecules.
D) Some viruses use DNA in their genomes.
E) Nucleic acid strands are held together by hydrogen bonds between complementary bases.