Final answer:
The adrenal gland, more specifically the adrenal medulla, secretes epinephrine, which prepares the body for fight-or-flight response by targeting organs like the heart and liver.
Step-by-step explanation:
The gland that secretes epinephrine, which triggers the fight-or-flight response, is the adrenal gland, specifically the adrenal medulla. The target tissue for epinephrine includes various effector organs such as the heart, blood vessels, and liver, among others. When epinephrine is released, it causes several physiological changes to prepare the body for rapid action. For example, it increases heart rate and blood pressure, dilates the airways, and stimulates glucose release from the liver to provide quick energy.
To answer the given question directly, the gland that secretes epinephrine is: A. Adrenal gland.