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: Surgery
Puerperal tetanus refers to: 
Select and explain. 
A. A complication of narcotic addiction, B. Result from unsterile instrumentation during labour, C. After months or years, Cl.tetani again multiply and cause disease, D. It is also known as tetanus neonatorum
B: Result from unsterile instrumentation during labour
Answer: B: Result from unsterile instrumentation during labour 
Explanation: It is also known as Post abortal tetanus.