Professor Santiago is researching the Presidential Election of 2020 and who supports each presidential candidate. She reviews studies completed by top political analyst, looks at statistics published regarding voter preference, and watches in-depth interviews with both supporters of each president. This is an example of .

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."

answer; deontological theory;