Final answer:
The nurse should monitor liver function tests (A) when administering chlorpromazine to a client with schizoaffective disorder.
Step-by-step explanation:
When caring for a client with schizoaffective disorder who has been prescribed chlorpromazine, the nurse should monitor liver function tests (A) during and immediately after IV administration of the drug. Chlorpromazine is metabolized by the liver, so monitoring liver function can help ensure the drug is being properly processed by the body. Monitoring serum creatinine (B), serum potassium (C), and complete blood count (CBC) (D) may be important for other aspects of the client's care, but they are not specifically related to the administration of chlorpromazine.