To solve this problem, we need to identify the parts of the human brain involved in regulating sexual behavior, excitement, pleasure, rage, and fear. Let's analyze each option:$\newline \bullet$Option 1: Limbic system \& hypothalamus$\newline$ - The limbic system is a complex set of structures in the brain that includes the hippocampus, amygdala, and other regions. It is involved in emotion, behavior, motivation, long-term memory, and olfaction.$\newline$ - The hypothalamus is a small region of the brain that plays a crucial role in hormone production and helps regulate body temperature, hunger, mood, and the autonomic nervous system. It is also involved in sexual behavior and emotional responses.$\newline$ - Therefore, this option correctly identifies the parts of the brain involved in these functions.$\newline \bullet$Option 2: Corpora quadrigemina \& hippocampus$\newline$ - The corpora quadrigemina are involved in visual and auditory reflexes, not directly in regulating emotions or sexual behavior.$\newline$ - The hippocampus is part of the limbic system and is involved in memory formation but not directly in regulating emotions or sexual behavior.$\newline$ - This option is incorrect.$\newline \bullet$Option 3: Brain stem \& epithalamus$\newline$ - The brain stem controls basic life functions such as breathing, heartbeat, and blood pressure, not emotions or sexual behavior.$\newline$ - The epithalamus includes the pineal gland, which regulates sleep-wake cycles, not emotions or sexual behavior.$\newline$ - This option is incorrect.$\newline \bullet$Option 4: Corpus callosum and thalamus$\newline$ - The corpus callosum connects the left and right cerebral hemispheres and facilitates interhemispheric communication, not directly involved in emotions or sexual behavior.$\newline$ - The thalamus acts as a relay station for sensory and motor signals to the cerebral cortex, not directly involved in emotions or sexual behavior.$\newline$ - This option is incorrect.$\newline$Therefore, the correct answer is Option 1: Limbic system \& hypothalamus.