Concept: This question tests your understanding of the major parts of the human brain and their specific functions, a fundamental topic in neural control and coordination.

Why (B) is correct: The statement says that voluntary muscle activity is started by the cerebellum. This is incorrect. Voluntary muscle activity is initiated by the cerebral cortex (specifically the motor cortex). The cerebellum plays a crucial role in coordinating voluntary movements, maintaining posture, balance, and muscle tone, but it does not initiate the movement itself.

Why other options are wrong:

• (A) Hypothalamus mainly controls ANS: This is correct. The hypothalamus is a major control center for the autonomic nervous system (ANS), regulating functions like body temperature, hunger, thirst, and emotional responses.
• (C) Medulla oblongata regulates involuntary activity of our body: This is correct. The medulla oblongata contains vital centers that control involuntary activities such as respiration, cardiovascular reflexes, and gastric secretions.
• (D) Thalamus acts as major coordinating centre for sensory and motor signaling: This is correct. The thalamus acts as a relay station for most sensory input (except smell) to the cerebral cortex and also plays a role in motor control.

Common Mistake: Students often confuse the roles of the cerebrum and cerebellum, especially regarding the initiation versus coordination of voluntary movements.

NEET Tip / Mnemonic: Remember that the Cerebrum is for Conscious thought and Commands (initiating movement), while the Cerebellum is for Coordination and Calibration of movements.

Correct Answer: (B)