Answer:
C). Emphasize the memorable role that books played in the speaker’s childhood.
Step-by-step explanation:
Allusions are primarily employed in a text to offer a deeper and greater context for understanding the author's message. The author in 'A Poem for My Librarian, Mrs. Long' alludes to particular writers and books as she wishes to throw light upon the notable role played by the books in her childhood. It helps the readers understand the special association that the speaker felt towards the books and how significant part they played in building her character. Thus, option C is the correct answer.