Out of the different methods to determine the time of death, which one do you think is most effective? why?

rigor mortis

Explanation:

Rigor mortis begins after two hours of death, starting from the head and slowly progressing to the feet. After twelve hours of death, the body will be at it's most rigor state. It's been said that it's possible to stand on the middle of a fully rigid body with only two platforms to support the head and feet, without snapping the body in half. After 36-48 hours, the body will resume soft-dead body status.

i believe your answer is mountains.