C. It helps the reader understand how the narrator felt as a young boy.
He compares the Lincoln School to the school he used to attend in Mazatlan. Through his narration in the first person the reader perceives Ernesto's momentary fears regarding the principal (is she friend or foe?) and his reliance on his mother's presence at the principal's office; understands how Ernesto experiences the English language and the way he is spoken to, with extremely simple words and expressions, and his relationship with his classmates, who also come from other countries, and can see how he gradually begins learn the language and feel at home in his new environment as a migrant.