Which of the following is considered the most positive sign of death?

The most positive sign of death is considered to be decomposition. Decomposition is a biological process that occurs after death, indicating that the body has ceased all vital activities and is undergoing changes due to microbial action. This is an absolute sign that life functions, including respiration and circulation, have permanently stopped.

In contrast, heart cessation signifies the stopping of the heart and can be seen as a moment immediately preceding death, rather than a sign that death has definitively occurred. A coma represents a state where an individual may still be alive but unresponsive due to severe brain injury or illness; therefore, it does not indicate death. Unconsciousness can also occur in living individuals due to various medical conditions and does not confirm death, as there may still be some residual level of brain activity.

Thus, decomposition clearly marks the transition into post-mortem changes, making it the definitive and most positive indicator of death in the context of forensic and medical assessments.