Read the passage from Harriet Tubman: Conductor on the Underground Railroad by Ann Petry.

Old Rit taught Harriet the words of that song that the slaves were forbidden to sing, because of the man named Denmark Vesey, who had urged the other slaves to revolt by telling them about Moses and the children of Israel. Sometimes, in the quarter, Harriet heard snatches of it, sung under the breath, almost whispered: "Go down, Moses. . . .” But she learned the words so well that she never forgot them.

What was Petry’s purpose for including this story about Harriet in the text?

A to tell what caused Harriet to first think of revolting against slaveholders
B to explain how Harriet’s family spent their time when they were not working
C to cause readers to feel sympathy toward Harriet because of the conditions in which she worked
D to show readers how Harriet and other enslaved people resisted rules imposed by slaveholders