Parathyroid hormone: a. increases osteoblast activity to release more calcium ions into the bloodstream b. increases osteoclast activity to release more calcium ions into the bloodstream c. increases osteocytes activity to release more calcium ions into the bloodstream d. none of the above

B

Explanation:

The parathyroid releases hormone that breaks down the bone to raise blood calcium level. Osteoclasts are responsible for breaking down the bone tissue.

the water is warmed up by the sun and then it evaporates into the atmosphere. the sunlight warms the water by its heat. water is then cooled down and condensation takes place. the water then finally returns back to the earth by the process of precipitation in the form of rain or ice.

explanation: