Statement A : The brain stem contains centres for controlling activities.
Statement B : Brain stem is very sensitive.

The brain stem consists of pons varoli, medulla oblongata, mid brain and diencephalon. The brain stem is the connection between brain and spinal cord. It contains centres for controlling many vital activities like respiration, body temperature, urge for eating and drinking etc. It also carries nerve tracts between the spinal cord and the higher brain structure.