Final answer:
Long-loop negative feedback involves the suppression of the anterior pituitary's stimulation by a target-gland hormone, regulating hormone concentration within a narrow, balanced range.
Step-by-step explanation:
Long-loop negative feedback is defined as the inhibition of the anterior pituitary by a target-gland hormone, which makes option c the correct choice. In this type of feedback mechanism, the target-gland hormone, such as thyroid hormones, inhibin, or glucocorticoids, reaches a level in the bloodstream where it signals the hypothalamus and anterior pituitary to cease stimulating further production. An example is the way testosterone and inhibin suppress the release of gonadotropin-releasing hormone (GnRH), follicle-stimulating hormone (FSH), and luteinizing hormone (LH). This regulation maintains the concentration of hormones within a narrow range, ensuring homeostasis.
This means that when a certain target-gland hormone reaches adequate levels in the bloodstream, it will inhibit the anterior pituitary gland from releasing more of the hormone that stimulates the target gland. This regulation mechanism helps maintain the concentration of hormones within a narrow range in the body.