Concept: This question tests the understanding of various parts and functions of the human brain and nervous system, including the cerebrum, cerebellum, pons, and the structure of a neuron.

Why (D) is correct:

• I. Association area is not responsible for regulation of sexual behaviour: This statement is correct. The association areas are primarily involved in complex functions like memory, communication, and intersensory associations. Regulation of sexual behavior is primarily controlled by the hypothalamus and limbic system.
• II. Cerebellum integrate information received from semicircular canals of the ear and the auditory system: This statement is correct. The cerebellum plays a crucial role in maintaining body posture and balance, integrating information from the vestibular system (semicircular canals) and other sensory inputs.
• III. Pons consist of fibre tracts that interconnect different regions of the brain: This statement is correct. The pons is a part of the brainstem that contains numerous fiber tracts, forming a bridge between different regions of the brain, particularly connecting the cerebellum with the cerebrum and other parts of the brainstem.
• IV. Inner part of cerebral hemisphere can be called as white matter: This statement is correct. The cerebral cortex (outer part) is made of grey matter, while the inner part of the cerebral hemisphere consists of tracts of nerve fibers, which constitute the white matter.
• V. The axon terminates into synaptic knob: This statement is correct. The distal end of an axon branches into fine terminals, each ending in a bulb-like structure called a synaptic knob (or terminal bouton), which contains neurotransmitters.

Since all five statements are correct, option D is the correct answer.

Why other options are wrong:

• Options A, B, and C are incorrect because they exclude one or more correct statements.

Common Mistake: Students might confuse the functions of different brain parts, especially between the cerebrum, cerebellum, and brainstem components like the pons and medulla. They might also mix up grey and white matter locations.

NEET Tip: Create a table summarizing the main parts of the brain (forebrain, midbrain, hindbrain) and their key functions. Pay special attention to the roles of the hypothalamus, limbic system, cerebellum, and the composition of grey and white matter.

Correct Answer: (D)