Cerebrum - voluntary activities. It is correct match It is the most important part of brain because it controls and regulates different part of brain.
All the body's voluntary actions are controlled by the motor cortex in the frontal lobe of the cerebrum.
Cerebellum - body balance. It is correct match The cerebellum coordinates voluntary movements such as posture, balance, coordination, and speech, resulting in smooth and balanced muscular activity.

It is also important for learning motor behaviours.
Medulla oblongata - pneumotaxic center. It is incorrect match
In the pons, the pontine respiratory group includes two areas known as the pneumotaxic center and the apneustic center.
Spinal cord - reflex action. It is correct match Spinal cord regulates and conducts the reflex action.

──────────────────────────────────────────────────────────────────────────────────────────