The answer would depend on the specific laws and regulations in the jurisdiction where the bus service operates, as well as the policies of the transit authority. However, generally:
B. Stop at the bus stop and inform the person with a disability that the bus is full, and they would need to wait for the next bus
is often the most commonly followed procedure in many regions. Bus drivers are usually required to ensure that individuals with disabilities have access to public transportation, but if the bus is at full capacity, they typically inform the waiting person that they will need to wait for the next bus.
Some systems may have specific policies about passengers in "priority" seats, but it's less common for drivers to remove passengers from the bus. Always refer to local transit regulations for the most accurate information.