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: Forensic Medicine
Nystens rule is regarding: 
Select and explain. 
A. Sequence of appearance of livor mortis, B. Postmortem changes in the retina, C. Sequence of appearance of rigor mortis, D. Postmortem changes in vitreous
C: Sequence of appearance of rigor mortis
Answer: C: Sequence of appearance of rigor mortis 
Explanation: Nystens rule states that there is a particular order in which rigor mortis appears and it diappears in the same order.