Answer:
Cerebellum.
Explanation:
Brain acts as the main control and coordination center of the body. Human brain is divided into three main parts - forebrain, midbrain and the hindbrain.
Cerebellum is the main part of hindbarin regulates the motor coordination and movement of the body. The involuntary and some sort of voluntary actions are controlled by the cerebellum. The contraction and relaxation of the smooth muscles is performed by cerebellum.
Thus, the correct answer is cerebellum.
