This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Techniques in molecular biology, Subject name: Biochemistry
PCR is primarily a 
Select and explain. 
A. DNA degradation technique, B. DNA amplification technique, C. DNA sequencing technique, D. All of these
B: DNA amplification technique
Answer: B: DNA amplification technique 
Explanation: PCR (Polymerase chain reaction) DNA amplification technique. Even a single copy of DNA can be amplified to billion-fold due to exponential amplification.