Which part of the brain is the largest, forms nearly two-thirds of the brain, and is responsible for thinking, memory, reasoning and intelligence?

1. The structure is the largest, about two-thirds of the brain. 2. The cerebellum is the second largest and handles balance, ruling out option A. 3. Medulla oblongata controls heartbeat and breathing, not thinking, ruling out option C. 4. The largest part handling thinking and memory is the cerebrum, option B. _Source: Samacheer Kalvi (TN SCERT) Class 10 Science, Unit 15 Nervous System "Cerebrum", p.229_