A nurse working in the acute care setting has just received laboratory data results. Which of the following clients should the nurse assess first?

A client recently diagnosed with rheumatoid arthritis whose platelet count is 148,000/mm3 (150,000 to 400,000/mm3)

A client who has hypothyroidism and whose magnesium level is 2.9 mEq/L (1.3 to 2.1 mEq/L)

A client who reported chest pain over the night whose potassium level is 5.9 mEq/L (3.5 to 5 mEq/()

A client who has a urinary tract infection whose white blood cell count is 14,000/mm2 (5,000 to 10,000/mm3)