Which of the following statements regarding the homeostasis regulation of blood calcium is false ?
a. Calcitonin inhibits the action of osteoclasts while having no effect on osteoblast activity.
b. This helps to lower the blood calcium level whenever it exceeds 11 mg/dL.
c. PTH is secreted by the parathyroid glands and raises blood calcium levels that are below 8.5 mg/dL.
d. The homeostasis of blood calcium is regulated by a negative feedback mechanism.
e. The three main organs that serve as the site for the regulation of blood calcium levels are the bones, the intestines, and the pancreas.