This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Death and postmortem changes, Subject name: Forensic Medicine
If a body is left undisturbed, for how long does post moem staining persists - 
Select and explain. 
A. Few hours, B. Few days, C. Few months, D. Persists till merges with discolouration of putrefaction
D: Persists till merges with discolouration of putrefaction
Answer: D: Persists till merges with discolouration of putrefaction 
Explanation: Postmoem staining occurs sholy after death and persists until putrefaction sets in which is also known as primary lividity. Dr.Narayana Reddys Synopsis of Forensic Medicine and Toxicology 27th edition pg. 76.