Answer:
Drive
Step-by-step explanation:
The drive theory of motivation is a theory according to which people are motivated to take certain actions to reduce the internal tension caused by needs that are not being satisfied.
According to this theory, behavior is one of the ways that an organism maintains balance (or homeostasis). The term "drive" refers to the state of tension caused by biological or physiological needs. Thus, the behavior is an external display of the person desire to satisfy the physical deficiencies he/she is going through.
In this example, Thalia suffers from insomnia. After trying many methods, she finds that it is easier for her to fall asleep once she starts counting backwards.
In the drive theory, the consequences of lack of sleep would be the drive, the tension that is produced by physiological needs. The behavior Thalia has (counting backwards) would be the external display she has to satisfy this deficiencies to be able to sleep and thus, maintain homeostasis.
Thus, the drive theory suggests that she continues this habit because it results in homeostasis