Which line from the quatrain best summarizes its central idea?

the answer is

Your beauty will never fade, because you will live forever in the lines of this poem.

To show the importance of education in changing his life.

Explanation:

"The Narrative of the Life of Frederick Douglass" is the personal account of a slave Frederick Douglass and how he got his freedom and became an abolitionist to help his fellow slaves to be free. The memoir is an important literary text that would be a part of the slave narrative form of writing.

In the given passage from the text, Douglass talks about how he first learned to read and write. But this experience was also cut short by his master who declared that "A ni g ger should know nothing but to obey his master—to do as he is told to do." And despite his master's opposition to an educated slave, Douglass recalls that it was at this moment he realized the significance of education for a slave.

Thus, the correct answer is that Douglass wanted to show the importance of education in changing his life.