Final answer:
Gina's aggressive behavior when she was fired is an example of the fight response of the stress response, specifically the fight-or-flight reaction, part of the body's alarm reaction to stress.
Step-by-step explanation:
When Gina's manager told her that she had been fired from her job and she began behaving aggressively, her reaction best exemplifies the fight response of the stress response, specifically the fight-or-flight reaction. This response is part of the general adaptation syndrome's (GAS) first stage called the alarm reaction, which is the body's immediate reaction to a threatening situation. The fight-or-flight response includes a series of physiological changes like increased heart rate and hormonal changes involving adrenaline and noradrenaline, which prepare the body for a quick reaction to the perceived threat. Gina's aggressive behavior is a behavioral expression of this fight response, which is less adaptive in modern psychological stressors compared to physical dangers faced by ancestors.