The right answer is the first phase of the general adaption syndrome.
The concept of stress was introduced by Hans Selye. He describes the mechanism of the adaptation syndrome, that is to say all the modifications that allow an organism to bear the consequences of a natural or operative trauma.
In fact, it is the double-perception of a state of divergence between a demand for adaptation at a given moment and the ability to cope with it. It is an energy expenditure. It can be positive or negative.
The stress syndrome evolves in three successive stages:
*"Alarm reaction": the defense forces are mobilized
*"Resistance stage": adaptation to the stressor
*"Stage of exhaustion": inexorably reached if the stressor is sufficiently powerful and acts a long time.
