Unlike RNA, DNA contains A. adenine. B. uracil. C. phosphate groups. D. thymine. Solution Answer is: Thymine Explanation: Base Pairing in DNA: A-T (Adenine-Thymine), G-C (Guanine-Cytosine) Base Pairing in RNA: A-U (Adenine-Uracil), G-C (Guanine-Cytosine) The phosphate group is present in both RNA and DNA..