Jack observes a dog. according to the principle of fundamental changes in the stimulus occur between the actual dog and jack's perception of the dog.

Transformation

Explanation:

Transformation is a process of changes in the thoughts of a person in psychology. This type of change occurs in thoughts and it cost high value. Transformation occurs in a different form in different contexts with a different value. For example when a person becomes religious before he was a nonreligious person. He starts to participate in religious work then it is a great transformation in the thought of a person.  

In the view of Piaget transformation is like any change occur in the experience that person experience before

A transformation occurs in psychoanalysis in which person gets to about their unconscious desires. So that Jack's perception for the dog is the example of transformation.

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."