Read the excerpt from the poem "Barbara Frietchie.”

All day long through Frederick street
Sounded the tread of marching feet:

All day long that free flag tost
Over the heads of the rebel host.

Which is most likely the author's purpose in using "all day long” in two successive rhyming couplets?

to help readers visualize the flag
to foreshadow what will happen next
to reflect what happened in the past
to emphasize a specific time frame