The motivation for the behavior of Amanda is:
A drive.
This refers to the external or internal influence which makes a person behave in a certain way so as to get a kind of reward or relief from something.
With this in mind, we can see that because Amanda experienced discomfort and after she put on a sweater, she realized that the cold was the source so her actions was motivated by a drive.
Hence, a drive is the motivating factor which person has to do something.
Read more about motivation here:
https://brainly.com/question/11871721
