Though I am no longer a medic, B equaling Basic depends on the state, county, city in which you live, and who is your medical director.
For example, in Wyoming, limitations are few, and basically comes down to the physician. I was both an industrial and emergency EMT, with the same physician advisor. As an industrial EMT-Basic, we could endotracheally intubate, administer medications, IV,IM,Sub-Q, all of the ACLS meds, defibrillate manually and the list goes on... skills somewhere between intermediate an paramedic.
As a emergency (ambulance) EMT, our skills were severely limited to driving, cleaning, chest compressions, basic limitations.
This may seem odd, but it is how the first paramedics were taught, with a physician showing them how.
I don't necessarily agree with this, however, for any level of care. Basic to Paramedic, I think in the United States our EMS personnel are extreemely under/uneducated... and then they complain that they don't get paid enough. Excellent examples of where we SHOULD be but are not are Austailia, Canada, and most of Europe, they require paramedics to complete a Bachelor's degree program in Paramedicine before they can practice. And their pay reflects it too, 40,000 to 70,000.
I, and many, would feel more at ease with personnel who were higher trained, but, of course, this would mean that they'd get paid more, and cost more, and since our healthcare system is a piece of POO right now, its not going to happen.
B