In operant conditioning studies, the subject’s motivational state is most typically operationally defined by:
(a) observing a subject's behavior over long period of time
(b) using a type of reinforcement that the experimenter knows that the subject usually likes
(c) depriving the subject of some desirable stimulus item for a period of time
(d) using a novel stimulus that the subject is sure to like

(C) depriving the subject of some desirable stimulus item for a period of time

Explanation:

Operant conditioning is a method of learning which occurs through reward and punishment of a behavior. This question talks about the motivational state of the subject, and option (c) defines the positive punishment- which says that people are being motivated to do something when they want to get something they like. And for that, it's necessary to note what are the likes and dislikes of a person, and you have to take that away for which they are being motivated to get.

manifest functions are the recognized and intended consequences of any social pattern, while latent functions are those unrecognized and unintended consequences. to analyze the manifest functions of any social institution, we have to study its contribution to the continuation of a group, community, or society.

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."