Also called adrenaline because it comes from the adrenal medulla, the main hormone for "fight or flight" is epinephrine insulin cortisol testosterone

The correct answer is A. Epinephrine

Explanation:

The "fight or flight response" is a physiological response that occurs due to a threat or attack and implies animals facing or avoiding the thread. This response involves the nervous system and also the adrenal medulla that produces the epinephrine or adrenaline which is one of the main hormones in the "fight or flight response" and causes muscular tension, rapid heartbeat, and dilatation of the pupil, which is part of the reactions in this response. Therefore, the hormone that is called adrenaline and that is one fo the main substances that cause the "fight and flight response" is the epinephrine.

many other transport proteins, often called pumps, move materials against a concentration gradient. active transport drives molecules across a membrane from a region of lower concentration to a region of higher concentration. this process, shown in figure 5.1, uses transport proteins powered by chemi- cal energy.