I don't think you mean above the medula oblongata, i think you mean something else because the connection between the two hemispheres is connected by the Corpus Callosum which is above of the thalamus.
The only answer that i can make sense of what you've wrote is A Cerebellum but i don't think you are correct forming your question. Where did you find the question
Obesity <span>is the most significant public health issue facing people in the U.S. today. The other categories has a low frequency to occur than Obesity.</span>