Refer(s) to manageable levels of stress for reasonable periods of time that generate positive emotions including satisfaction, excitement, and enjoyment. ob

The following is missing for the question to be complete:

A. Functional

B. Dysfunctional

C. Appropriated

D. Distilled

    Functional stress

Explanation:  Stress is usually associated with a poor condition, though it may not always be the case. There is also moderate stress that stimulates the brain to, say, an activity when learning new things, that is, memorising. In addition, mild stress creates a certain amount of adrenaline that contributes to making the activity more pleasant, and such mild stress is called functional stress. Such stress can be some positive challenge, say at work, which makes us move, encouraged to do the job as best we can. That is why functional stress is a subject of study within organisational behaviour to encourage performance and workers and how certain incentives affect the general mood and activities of workers in the work environment.

intimacy, passion and commitment are the components of a interpersonal relationship emphasized in the triangular theory of love by robert sternberg.

the triangular theory of love says love can be comprehend as this componest form the vertices of a triangle.  

intimacy relates to feelings such as of closeness and connection;

passion relates the drives that brings people together, as physical attraction.

commitment relates to the being in a long-term relationship.