This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Injuries, Subject name: Forensic Medicine
True about Rigor mortis: 
Select and explain. 
A. Does not occur in fetus less than 7 months, B. Involves voluntary muscles only, C. Lasts for 12 - 24 hours in summer, D. Starts in chin
A: Does not occur in fetus less than 7 months
Answer: A: Does not occur in fetus less than 7 months 
Explanation: Ans. (A). Does not occur in fetus less than 7 monthsRigor mortis involves both voluntary and involuntary muscles, earlier in involuntary muscles.Rigor mortis is not seen inRigor mortis is tested byFetus < 7 monthsQHeat stiffeningQEmbalmingQTrying to lift eyelidsLowering the jawBending neck & thighsInstrument:Electromyogram