Answer: option D - the breakdown of essential proteins of the brain and heart
Step-by-step explanation:
During starvation (food deprivation), the body cells begins to utilize the glycogen reserves in the liver and muscle. Then, it switches to the fats (stored in the adipose tissues).
If starvation persists, the body turns to the proteins for energy derivation. At this stage, the person's DYING STATE is usually visible because the muscles of the body shrinks greatly.
Note that DEATH set in when essential proteins of the BRAIN and HEART are metabolized to produce energy due to the vital functions both organs do in the overall body processes.