A Patient Comes to the Clinic and Tells the Nurse

A patient comes to the clinic and tells the nurse she might be pregnant.She has migraine headaches.The physician prescribes dihydroergotamine (D.H.E.45) .The nurse explains to the patient that this drug is being used for which of the following reasons?

A) This agent dilates vessels in migraine headaches.
B) This agent does not have oxytocic effects.
C) This agent has no toxic effects.
D) This agent does not cause dependence.