Concept: This question tests your knowledge of the major parts of the human brain and their anatomical locations as seen in a sagittal section.

Why (B) is correct:

• I - Cerebrum: The largest, uppermost part of the brain, responsible for higher functions like thought, voluntary action, and sensory processing. Label I clearly points to this region.
• III - Pons: Located in the brainstem, inferior to the midbrain and superior to the medulla oblongata. It acts as a bridge connecting different parts of the brain, particularly the cerebellum and the cerebral cortex. Label III correctly indicates the pons.

Why other options are wrong:

• (A) III-Midbrain: Label III is the pons, not the midbrain (which is superior to the pons). IV-Cerebellum: Label IV points to the medulla oblongata, not the cerebellum (which is posterior to the brainstem).
• (C) II-Corpus callosum: Label II points to the thalamus, not the corpus callosum (which is a band of nerve fibers connecting the cerebral hemispheres, located superior to the thalamus). IV-Medulla: Label IV correctly points to the medulla, but II is incorrect.
• (D) I-Cerebral hemispheres: Label I points to the cerebrum, which consists of cerebral hemispheres. II-Cerebellum: Label II points to the thalamus, not the cerebellum.

Common Mistake: Students often confuse the different parts of the brainstem (midbrain, pons, medulla) and their relative positions, as well as the structures deep within the cerebrum like the thalamus and corpus callosum.

NEET Tip / Mnemonic: Remember the brainstem order from top to bottom: My Parents Made (Midbrain, Pons, Medulla). The cerebellum is posterior to the pons and medulla.

Correct Answer: (B)