This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Metabolism of nucleic acids, Subject name: Biochemistry
Not present in DNA 
Select and explain. 
A. Uracil, B. Thymine, C. Cystosine, D. Adenine
A: Uracil
Answer: A: Uracil 
Explanation: Repeated question