The correct answer is known as the "reticular formation"/
The Reticular Formation has a function of projections to the thalamus and cerebral cortex that permit it to exert some control over which sensory indicators attain the cerebrum and come to our conscious interest. It plays a relevant position in states of awareness like alertness and sleep, wherein based on the given situation, Alice was able to block the sound from the class, in order for her to focus on her term paper.