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: Gynaecology & Obstetrics
A negative pregnancy test excludes the diagnosis of which aboion? 
Select and explain. 
A. Threatened aboion, B. Ectopic Aboion, C. Both, D. None
A: Threatened aboion
Answer: A: Threatened aboion 
Explanation: A;Threatened aboion