A Postoperative Client Received Morphine in the Recovery Room

A postoperative client received morphine in the recovery room. On assessment, the nurse notes that the client's respiratory rate is 6 breaths per minute and that the client has a decreased level of consciousness. The anesthesiologist orders naloxone (Narcan) . The nurse administers this medication with the knowledge that this drug is a(n) :

A) respiratory stimulant.
B) opioid antagonist.
C) bronchodilator.
D) anticonvulsant.