Question: Which one of the following statements concerning the difference between DNA and RNA is correct? Need Assignment Help? Question options: a) DNA molecules can interact to form complex tertiary structures related to the novel functions of DNA. b) The four nucleotide building blocks of RNA include thymosine, cytosine, guanine, and adenine. c) RNA exists typically as a single-stranded polymer that is much shorter than double-stranded DNA. d) DNA is composed of a sugar unit, ribose, with an added hydroxyl group at the 2' position.