Final answer:
The nurse should report complaints of numbness and tingling in the fingers to the HCP, as this could indicate nerve damage or compromised circulation.
Step-by-step explanation:
The finding that a nurse should report to the Health Care Provider (HCP) when assessing a patient who is scheduled for surgical fixation of a compound fracture of the right ulna is C) Complaints of numbness and tingling in the fingers. While the presence of peripheral pulses, a capillary refill time of less than 3 seconds, and warmth and pink color of the fingers are all normal findings, complaints of numbness and tingling can indicate nerve damage or compromised circulation due to the fracture or swelling, which may require immediate attention to prevent further complications.