The answer is A, the immune system
Answer: to defend itself
Explanation:
This natural reaction prepares you to either flee or protect yourself in dangerous situations. Your heart rate increases, your adrenal gland releases cortisol (a stress hormone), and you receive a boost of adrenaline, which increases energy. This fight-or-flight response occurs in the alarm reaction stage.
Since smokers are not allowed to smoke within restaurants, office buildings, airports, schools, and many other places, far fewer people are being exposed to secondhand smoke. People with asthma and allergies to cigarette smoke are now able to breathe more easily as well. Children are no longer being exposed to secondhand smoke in spaces outside of their homes.
Whats the question though???????????????????
