They are our bodies preferred source of energy for everything we do and before using carbohydrates for fuel, our bodies have to break these compounds down into simple sugars.
The cerebrum controls the higher brain functions such as speech, writing, etc. The cerebellum deals with the involuntary stuff. The other 2 are nowhere near what you are looking for. B - Cerebrum is your answer.
Here one of the answer Red Cedar Tree
I think that 3 is C and 2 is B