When Having Difficulty Drawing Blood from a Patient, the Nurse

When having difficulty drawing blood from a patient, the nurse knows that it is necessary to avoid leaving the tourniquet on longer than 1 minute because

A) In patients with hypertension, doing so can cause an increase in blood pressure.
B) Doing so can cause discomfort if the patient's skin is fragile.
C) Doing so can cause edema.
D) Doing so can alter laboratory results.