A new drug named AGON-CaSR has been developed that is an agonist at calcium-binding sites of CaSRs (Calcium-Sensing Receptors) in plasma membranes of parathyroid gland cells.
Healthy Person P receives regular doses of AGON-CaSR as part of a clinical trial. When AGON-CaSR levels in the extracellular spaces surrounding parathyroid gland cells increase in Healthy Person P, this leads to
A. A decrease in the levels of calcium in the blood plasma.
B. A decrease in the levels of parathyroid hormone (PTH) in the blood plasma.
C. An increase in the amount of PTH binding to PTH Receptors in bone.