Answer:
Stress response
Step-by-step explanation:
Stress response is how the body responds to an emergency situation or a perceived threat. It can also be referred to as "fight or flight" response. When the body senses a perceived threat or a sudden change in environmental demand, it turns on the stress response of the body and this then result to physiological changes such as the release of chemical substance like cortisol and adrenaline, increase in pulse, muscle tension etc.
Therefore the sudden increase in muscle tension as a result of anxiety is an example of stress response.