Can you rent a class b truck?

Class B isn't a category of truck - it's a type of licence needed to operate a heavy duty truck not towing a trailer in excess of 10,000 lbs. Those would be Class 7 (GVWR of 26,001 to 33,000 lbs) and Class 8 (GVWR in excess of 33,000 lbs.) trucks. Penske and Ryder Truck Rental both lease these classes of truck.