Assertion: The alarm reaction stage in the General Adaptation Syndrome (GAS) is characterized by the release of adrenaline for the fight or flight response.

Reasoning: The activation of the hypothalamus during the alarm reaction stage triggers the release of stress hormones.

The assertion is true, but the reasoning is false.

The assertion is true as the alarm reaction stage in GAS is indeed characterized by the release of adrenaline for the fight or flight response. The reasoning is not true as the activation of the adrenal-pituitary-cortex system triggers the release of stress hormones.