Cells that bisphosphonate medications primarily act on are:

Correct answer: B. Osteoclasts

• A. Incorrect. Bisphosphonates do not primarily target osteoblasts, though reduced osteoclast activity eventually affects bone formation coupling.
• B. Correct. Bisphosphonates (alendronate, zoledronate, denosumab acts differently but the question specifies bisphosphonates) primarily act on OSTEOCLASTS. They are incorporated into bone matrix, and when osteoclasts attempt resorption, they ingest the bisphosphonate, which then disrupts osteoclast function (inhibiting the mevalonate pathway), leading to osteoclast APOPTOSIS (death). The net result is reduced bone resorption.
• C. Incorrect. Odontoblasts are not the target of bisphosphonates.
• D. Incorrect. Bisphosphonates have no direct action on fibroblasts.