Psychologists are ethically bound to keep material about their patients confidential except: a. when someone is in danger. b. when discussing the case as part of a college class. c. when writing up a case study for a journal article. d. when discussing the patient with a spouse.

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."