What statement by a client who is 24 hours post-subtotal thyroidectomy requires an immediate investigation by the nurse?

A. Increased urination due to IV fluids is common and not immediately concerning.B. Comfort with an elevated head of bed is typical postoperatively.C. A tight dressing could indicate swelling or a potential complication such as hematoma, which can compromise the airway and requires immediate assessment.D. Dizziness upon standing is common and not as urgent as potential airway compromise.