First researched the forensic study of a dead body to determine cause of death.

I agree with the person above.
I also believe that Leonardo da Vinci first researched the forensic study of a dead body to determine cause of death. Maybe not to determine the cause of death per se, but he was interested in human anatomy, which can be seen in one of his sketches or drawings called Vitruvian Man.

Iwould say the answer would be b