A nurse is caring for a client who is 1 day postoperative following a transsphenoidal hypophysectomy. While assessing the client, the nurse notes a large area of clear drainage seeping from the nasal packing. Which of the following should be the nurse's initial action?

A. While documentation is important, the nurse must first determine the nature of the drainage. B. After a transsphenoidal hypophysectomy, clear nasal drainage may indicate a cerebrospinal fluid (CSF) leak. CSF tests positive for glucose, so checking the drainage helps confirm this complication. C. Cultures are used to detect infection, but the immediate concern is whether the drainage is CSF. D. The nurse should first test the drainage for glucose to verify whether it is CSF before contacting the provider with critical information.