Which piece of evidence best advances the author’s purpose of revealing the united states’ goal of progress?
a “the fair’s motto was ‘living in the space age.’” (“hovering above seattle,” paragraph 2)
b “the city of seattle designated the space needle a historic landmark in 1999.” (“hovering above seattle,” paragraph 8)
c “in the 20th century, st. louis civic leaders envisioned a memorial that celebrated the city’s role in the nation’s westward expansion.” (“the gateway arch,” paragraph 1)
d “they hoped it would breathe new life into the city and become a major tourist attraction.” (“the gateway arch,” paragraph 1)