A Client Is Receiving Lithium (Eskalith) and Asks the Nurse

A client is receiving lithium (Eskalith) and asks the nurse why their blood has to be drawn so often. What is the best response by the nurse?

A) "To detect side effects before they become a problem."
B) "To be sure the medication is working properly."
C) "To determine if your body is responding as it should."
D) "To be sure you have the correct amount of medication in your system."