I think the answer you are looking for is that the stomach is the fourth level of organization.
The organ which plays the primary role in prompting individuals to seek food is the brain. The brain is one of the most important organ of the nervous system. It is comparable to the CPU of a computer. It is repsonsible of processing information that it is receiving from all the senses and send the message back to the organs for a response.
C. The Bering Land Bridge once connected what would be Russia and North America but the the movement of these continents separated the land bridge
