This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Physiology
In a DNA molecule adenine always forms a linkage with 
Select and explain. 
A. Guanine, B. Cytosine, C. Thymine, D. Uracil
C: Thymine
Answer: C: Thymine 
Explanation: None