The theoretical perspective most concerned with the way that powerful people define illness is: a. symbolic interactionist b. conflict c. functionalist d. feminist

The best response of the options provided is Option B: Conflict theory.

Explanation:

The best choice of the options provided is conflict theory because conflict theorists take a critical stance toward existing social arrangements like the way that illness is defined. This can affect the access that people without power have to services or to livelihood, if the way that the powerful define illness works to their disadvantage in some way. An example would be denying someone disability status because their condition is not recognized as an illness that can affect productivity. This could make it so the person who is less powerful has to continue working despite their illness or disability and it may deny them benefits.  

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."