A woman had unprotected intercourse 36 hours ago and is concerned that she may be-come pregnant ...

A woman had unprotected intercourse 36 hours ago and is concerned that she may be-come pregnant because it is her fertile time. She asks the nurse about emergency con-traception. The nurse tells her that:
 
  a. It is too late; she needed to begin treatment within 24 hours after intercourse.
  b. Preven, an emergency contraceptive method, is 98 effective at preventing pregnancy.
  c. An over-the-counter antiemetic can be taken 1 hour before each contraceptive dose to prevent nausea and vomiting.
  d. The most effective approach is to use a progestin-only preparation.