A Patient Receiving Aminophylline (Theophylline)by Continuous IV Infusion for a Severe

A patient receiving aminophylline (Theophylline) by continuous IV infusion for a severe asthma attack asks why a blood sample must be drawn.What is the nurse's best response?

A) "The blood level of this drug that causes dangerous side effects is close to the level needed to help open the airways."
B) "The blood test helps us evaluate how well the drug is working to open your airways and improve your oxygen intake."
C) "The blood test helps determine how much of this drug you are making naturally and how much we are giving you."
D) This blood tests assesses whether you are developing an allergy to this drug."