A. The cerebellum is primarily involved in motor control, balance, and coordination rather than regulating wakefulness. B. The amygdala is involved in emotion regulation, particularly fear and anxiety, rather than maintaining wakefulness. C. The reticular activating system (RAS) plays a crucial role in maintaining alertness and wakefulness by regulating the sleep-wake cycle and cortical arousal. D. The hypothalamus plays a role in regulating various autonomic functions and the sleep-wake cycle but is not as directly responsible for maintaining wakefulness as the RAS.