Which of the following is an example of a feedback loop in the body apex

(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.

lunar landing mission. apollo 11 was the first manned mission to land on the moon. the first steps by humans on another planetary body were taken by neil armstrong and buzz aldrin on july 20, 1969. the astronauts also returned to earth the first samples from another planetary body.

explanation: