A Patient Requiring Frequent Blood Samples Tells the Nurse Preparing

A patient requiring frequent blood samples tells the nurse preparing to obtain a specimen that "the best vein is here in my right elbow on the side." The nurse observes that the vein is visible and palpable and has mild ecchymosis, but no pain.Which action by the nurse is most appropriate?

A) Acknowledge the patient's information, but tell the patient it is better to use another site this time.
B) Begin by applying the tourniquet to the left arm to assess potential sites while reassuring the patient of your expertise.
C) Examine the site the patient indicates and attempt to obtain the specimen there first.
D) Thank the patient for the information, but do not use a previously used vein.