The part of the brain which maintains the posture and balance of the body is:

As stated in the chapter: "Think about activities like walking in a straight line, riding a bicycle, picking up a pencil. These are possible due to a part of the hind-brain called the cerebellum. It is responsible for precision of voluntary actions and maintaining the posture and balance of the body." Hence option (C) is correct.

Why the other options are wrong:

(A) Pons is part of the hind-brain but it relays signals and helps regulate breathing; it is not specifically credited with posture/balance in the text.

(B) Cerebrum is the main thinking part of the fore-brain, responsible for receiving sensory impulses, interpreting them, and controlling voluntary muscle movement — not specifically posture and balance.

(D) Medulla, in the hind-brain, controls involuntary actions such as blood pressure, salivation and vomiting, not posture and balance.