Read the excerpt from the poem "Barbara Frietchie.” Up rose old Barbara Frietchie then,
Bowed with her fourscore years and ten;

Bravest of all in Frederick town,
She took up the flag the men hauled down;

How do the rhyming couplets move the action forward?

by including descriptive details about setting
by connecting important plot points
by illustrating the author's purpose
by using the same number of syllables