The initial reaction of the body to stress is called the fight-or-flight response the lonely stage the resistance stage the exhaustion stage

The correct answer is- the fight-or-flight response

Explanation:

During stress condition, the sympathetic nervous system becomes activated and send signals to the adrenal gland to release stress hormone like epinephrine (adrenaline) and norepinephrine which triggers the fight and flight response of the body.  

This response is marked by various changes in the body like sweating, increased heartbeat, deep breathing, dilation of pupils, increment of blood glucose level, more focus on threat, etc.  

So fight and flight response is the initial reaction of the body towards any threat or stress which helps the body to fight with the threat or to avoid the threat.