As far as I know, the adrenal glands, when submitted under pressure such as the one described in the example, secrete a substance known as epinephrine which has the tendency of increasing the affected person's heart rate and breathing.
Answer:

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Wouldn't the answer be extinction?
There are so many examples for that in different areas, like steroidal compounds experiment carried out in our lab recently.
Here's one link: hhttp://www.alfa-chemistry.com/products/steroidal-compounds-8.htm
Answer:
A) vesicle
I think this is the right answer, i may be incorrect.
Through chemical bonds to form larger particles called molecules