A nurse is assessing a patient who started taking valproic acid to treat seizures and presents for the follow up with a yellowing of the eyes and skin. Which of the following laboratory tests should the nurse prioritize to evaluate these symptoms and guide further care?

A. Complete blood count with platelet count: Valproic acid can rarely cause thrombocytopenia, but yellowing of the eyes and skin (jaundice) indicates a potential liver issue rather than a blood cell abnormality. CBC is not the first priority here. B. Liver function tests: Jaundice suggests hepatotoxicity, a known serious adverse effect of valproic acid. Liver function tests (AST, ALT, bilirubin) are essential to assess liver injury and guide whether the medication should be discontinued or adjusted. C. Serum sodium level: Serum sodium is not related to the symptoms of jaundice. While valproic acid does not typically affect sodium levels, hyponatremia would not explain yellowing of the skin or eyes. D. Blood glucose level: Blood glucose monitoring is unrelated to valproic acid-induced jaundice. Hyperglycemia or hypoglycemia would not present with yellowing of the skin or eyes.