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: Microbiology
Prophage is defined as: 
Select and explain. 
A. Inseion of viral nucleic acid into bacteria by bacteriophage, B. First cycle of division of bacterial nucleic acid, C. Last cycle of division of bacterial nucleic acid, D. Integrated temperate bacteriophage genome into bacterial chromosome
A: Inseion of viral nucleic acid into bacteria by bacteriophage
Answer: A: Inseion of viral nucleic acid into bacteria by bacteriophage 
Explanation: Ans. is. 'a' i. e., Inseion of viral nucleic acid into bacteria by bacteriophage