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: Psychiatry
Three years back a woman suffered during an earthquake and she was successfully saved. After recovery, she has nightmares about the episode and she also gets up in the night and feels terrified. The most probable diagnosis is - 
Select and explain. 
A. Major depression, B. Post-traumatic stress disorder, C. Mania, D. Schizophrenia
B: Post-traumatic stress disorder
Answer: B: Post-traumatic stress disorder 
Explanation: Similar to previous question, nightmares about the episode (intrusion of thoughts about event) after a life threatening event (earthquake) suggest the diagnosis of PTSD.