Final answer:
Bone resorption is carried out by osteoclasts, which are cells responsible for breaking down the bone and do not originate from osteogenic cells.
Step-by-step explanation:
Bone resorption, the process of breaking down bone tissue, is a vital part of the body's ability to repair and remodel bone as well as regulate calcium levels. The cell responsible for bone resorption is the osteoclast. These multinucleated cells are found on bone surfaces and are derived from monocytes and macrophages, which are types of white blood cells. Unlike osteoblasts, which are involved in bone formation, osteoclasts are continually breaking down old bone. This process is influenced by various hormones and vitamins, such as the parathyroid hormone, vitamin D, thyroid hormones, and cortisol, among others. Therefore, in response to the question, bone resorption requires the activity of osteoclasts (option a). It is important to note that osteoclasts do not originate from osteogenic cells.