Final answer:
The method of hormone elimination where enzymes break down the hormone, is known as metabolism, which is the correct answer to the student's question.
Step-by-step explanation:
The ability of enzymes in the blood, liver, kidneys, or other target tissues to break down the hormone and excrete it describes the process of metabolism. This method of hormone elimination involves enzymatic modification in the blood and/or in the liver to inactivate hormones such as catecholamines, steroids, and thyroid hormones. Once metabolized, these substances are often conjugated with components like glucuronic acid to render them more soluble, facilitating their excretion through the urine or bile.
In summary, the process you're asking about, related to the modification and subsequent elimination of hormones, is best described as metabolism, which is option 2.