Final answer:
The earliest stage of the general adaptation syndrome is the alarm reaction, which is similar to the fight-or-flight response. It involves physiological reactions that prepare the body to manage a threatening situation.
Step-by-step explanation:
The earliest stage of the general adaptation syndrome, also known as GAS, is the alarm reaction. During this stage, the body's immediate physiological reactions to a threatening situation or emergency are similar to the fight-or-flight response. It involves a cascade of physiological reactions that provide the body with the energy to manage the situation, such as increased heart rate and blood pressure.