Think about the dred scott ruling, the debate over slavery that led up to it, and the upcoming presidential election of 1860.

The case will play a big part in the campaign.

The issue will sharply divide the parties.

The issue will sharply divide the nation.

sample response ^

Explanation:

d. i assume the underlined word is "role." reformat if it isn't.

explanation:

role is closest to part because when replacing words, "playing a vital decision," "playing a vital activity," and "playing a vital dollar" don't make logical sense. the only meaningful choice is "playing a vital part."

this fits one of merriam-webster's definitions of role: "a function or part performed especially in a particular operation or process."