Hypercalcemia workup ddx

Following the recheck of a patient's serum calcium levels, the corrected total calcium is found to be elevated. Which of the following is NOT an appropriate next step in the workup for hypercalcemia?

1: Checking parathyroid hormone (PTH) levels
2: Ordering a 24-hour urine calcium excretion test
3: Administering a bolus of normal saline
4: Testing for parathyroid hormone-related protein (PTHrP)