That would be a class C (though they may advertise it as a "class B+", which is something pretty much made up by marketing).
The class distinctions are based on what chassis the motorhome maker started out with. A class A is built on a bare or custom chassis, and all the body work comes from the motorhome maker. A class B is built inside of a van, often with a raised roof; the walls are all from the vehicle maker. A class C is built on a cutaway chassis (or a cab chassis), with the driving compartment made by the vehicle builder and the house part in back made by the RV maker.
For some reason I don't entirely understand, bus conversions are generally grouped with class A's rather than class B's. I suppose part of it may be the size and amenities are more typical of class A's, and perhaps the argument is made that the bus was built on a more or less custom chassis to begin with.