General Adaptation Syndrome is characterized by a reduction in immune system functioning that will be temporary if the stress is over quickly.

The Alarm Stage.

Explanation:

General Adaptation Syndrome is the different stages of stress developed by Hans Selye, a researcher.

The stages of stress, according to GAS are:

Alarm stage Resistance stage Exhaustion Stage

In the Alarm Stage of GAS, when faced with stressful situations, the body reacts as in "fight-or-flight" response. In this stage, an alarm signal is sent to the body by the brain, giving them warning of the dangerous situation. In this stage, a person facing a dangerous situation, while having faster heart-beat rate. This leads to a reduction in immune system functioning.