You have been playing the piano since you were five years old. when asked to play a relatively easy piece, like chopsticks, you do so with very little effort. during this performance, your is active.
a) dorsal premotor cortex
b) supplementary motor area
c) premotor cortex
d) ventral premotor cortex

B) Supplementary motor area.  

Explanation:

The supplementary motor area is the part of the brain that controls the movements in the body. It just located at the mid-line surface area of the brain. In human beings, this area is not apparent. The SMA area is direct projects the neurons in the spinal cord that sent the message to the brain and play a role in controlling the movement of the body. It controls the external movement of the body and the postural stability of the body. It controls the movement on both sides of the body and controls the sequence of the movement.

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