What kind of drug works by blocking the action of a receptor?

You are evaluating a 28-year-old female patient who was the belted driver in a car-versus-tree motor vehicle crash. She is also 30 weeks' pregnant. She is complaining of severe abdominal pain with cramping, and you can see blood soaking into her shorts and onto the driver's seat. As you prepare for a rapid extrication, you are worried that she may have experienced:

A) b. Femoral artery laceration B) a. Abruptio placentae C) c. Liver laceration D) d. Premature labor

The National Plan & Provider Enumeration System was developed by:

A)HIPAA B)DEA C)CMS D)NPI