To solve this problem, we need to identify which part of the brain is responsible for thermoregulation. Let's analyze each option:$\newline \bullet$Cerebrum:$\newline$ - The cerebrum is the largest part of the brain and is responsible for higher brain functions such as thought and action.$\newline$ - It is not primarily involved in thermoregulation.$\newline \bullet$Hypothalamus:$\newline$ - The hypothalamus is a small region of the brain located below the thalamus.$\newline$ - It plays a crucial role in maintaining homeostasis, including the regulation of body temperature.$\newline$ - The hypothalamus acts as the body's thermostat, detecting changes in body temperature and initiating responses to adjust it.$\newline$ - Therefore, the hypothalamus is responsible for thermoregulation.$\newline \bullet$Corpus callosum:$\newline$ - The corpus callosum is a band of nerve fibers that connects the left and right cerebral hemispheres.$\newline$ - It facilitates communication between the two hemispheres but is not involved in thermoregulation.$\newline \bullet$Medulla oblongata:$\newline$ - The medulla oblongata is part of the brainstem and controls autonomic functions such as breathing and heart rate.$\newline$ - It does not primarily regulate body temperature.$\newline$Based on this analysis, the correct answer is:$\newline$Option 2: Hypothalamus