In a study of education in the united states, would emphasize the daily activities and the various forms of communication between teachers and students. they would also examine the influence of peer groups and look at the reaction when school rules are either broken or followed.

researches (psychologists or phonoaudiologists)

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."

answer; environmental science;