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: Biochemistry
mRNA is a complimentary copy of ? 
Select and explain. 
A. TRNA, B. RRNA, C. Ribosomal DNA, D. A single strand of DNA
D: A single strand of DNA
Answer: D: A single strand of DNA 
Explanation: D i.e. A single strand of DNA