Answer:
(C) One gland causes calcium ions to be released; another gland causes them to be absorbed
Explanation:
A feedback loop can be described as a system in which the product produced can either amplify the system or inhibit the system by which it is produced. If the product amplifies the system it is a positive feedback loop. If the product inhibits the system, it is a negative feedback loop. However, most of the hormones have a negative feedback loop.
When a gland releases a hormone that causes a product in blood in its required concentration the product itself feeds back and other gland cause them to be absorbed.
