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
Gene transfer in bacterial system by 
Select and explain. 
A. Transformation, B. Transduction, C. Conjugation, D. Location
A: Transformation
Answer: A: Transformation 
Explanation: Transformation is one of three processes for horizontal gene transfer, in which exogenous genetic material passes from bacterium to another, the other two being conjugation (transfer of genetic material between two bacterial cells in direct contact)