Answer- D- Putrefaction
Putrefaction is the decomposition of the body carried out by the microbial action. After cessation of hemostasis, the natural flora of the body migrates from the gut to the blood vessels and spreads all over the body.
External micro-organisms enter the body through the alimentary canal, respiratory tract, and open wounds. In the absence of body defenses/immune mechanisms, the microbes keep growing, as they feed upon the proteins and carbohydrates of the blood and body parts.
The principal bacterial agent causing putrefaction is the gram-positive, anaerobic, and rod-shaped Clostridium welchii.
It releases lecithinase, which causes hydrolysis of lecithin present in the blood cells, causing their lysis. Putrefaction begins within an hour of death, but the peak activity of the microbes occurs around the 24-hour timeframe.