### Core Concept
Osteoporosis is a metabolic bone disease characterized by decreased bone mass and density, leading to increased risk of fractures. In osteoporosis, bone resorption exceeds bone formation, resulting in net bone loss. Agents that inhibit bone resorption are used to treat osteoporosis.

### Why the Correct Answer is Right
Bone resorption is primarily mediated by osteoclasts, which break down bone matrix through the action of acid and enzymes. Bisphosphonates, such as alendronate, risedronate, and ibandronate, act by inhibiting osteoclast-mediated bone resorption. They bind to hydroxyapatite in bone, inhibiting osteoclast activity and thereby reducing bone resorption.

### Why Each Wrong Option is Incorrect
**Option A:** Teriparatide is an anabolic agent that stimulates bone formation by increasing osteoblast activity. It does not inhibit bone resorption.
**Option B:** Raloxifene is a selective estrogen receptor modulator (SERM) that acts as an estrogen agonist in bone, thereby promoting bone formation and density. While it may have some effects on bone resorption, its primary mechanism is through anabolic effects.
**Option C:** Strontium ranelate has both anabolic and catabolic effects on bone, but its primary mechanism is through inhibition of bone resorption, making it a correct answer.

### Clinical Pearl / High-Yield Fact
Bisphosphonates are the most commonly used agents for the treatment of osteoporosis due to their effectiveness in inhibiting bone resorption and increasing bone density.

### Correct Answer:
C. Strontium ranelate