Why is an important technological advance

Every day new technological resources emerge to prove that man, as well as creator, is also the adapter of these advances. While facilitating the dynamics and work process, they can replace some activities that, not far away, needed human action.

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."