**Core Concept**
Bone remodeling is a dynamic process involving the coordinated action of osteoclasts and osteoblasts to maintain bone homeostasis. This process involves the resorption of old bone tissue by osteoclasts, followed by the deposition of new bone tissue by osteoblasts.

**Why the Correct Answer is Right**
The correct answer is related to the regulation of bone remodeling. The process is tightly regulated by various hormones, growth factors, and local factors, including parathyroid hormone (PTH), calcitonin, vitamin D, and growth factors like TGF-β and BMPs. These factors act on osteoclasts and osteoblasts to regulate their activity and maintain bone homeostasis.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because bone remodeling is not limited to the remodeling of compact bone. Both compact and cancellous bone are involved in the remodeling process.

**Option B:** This option is incorrect because the activation frequency of osteoclasts is not directly related to the lifespan of osteoclasts. The lifespan of osteoclasts is typically around 2-4 weeks, but their activation frequency can vary depending on the physiological demands of the body.

**Option C:** This option is incorrect because the primary function of osteoblasts is not to resorb bone tissue. Osteoblasts are responsible for the deposition of new bone tissue, whereas osteoclasts are responsible for the resorption of old bone tissue.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that bone remodeling is a continuous process that occurs throughout life, and any disruption to this process can lead to bone disorders such as osteoporosis or osteopenia. Factors that affect bone remodeling include hormonal imbalances, nutritional deficiencies, and genetic disorders.

**Correct Answer: B. The lifespan of osteoclasts is typically around 2-4 weeks.**