All of the activities designed to get a candidate elected to public office are called

All the activities designed to get a candidate elected to public office are called campaigns. A political campaign is an organized effort, which seeks to influence the creation of opinions and decision-making within a particular group. In democracies, political campaigns often refer to electoral campaigns in which representatives are elected or decides on referendums. In today's election campaigns, the influence is focused on general elections, the prime minister or the president of the state, as well as the position in public offices.

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."