Final answer:
On duty hours for a bus driver include making repairs, attending inspections, and waiting for assistance after a breakdown, thus the correct answer is all of these activities combined.
Step-by-step explanation:
The on duty hours for a bus driver encompass various activities that are part of the job responsibilities. According to the information provided, time spent making repairs, time spent attending an inspection, and time spent awaiting assistance after a breakdown or accident all count as on duty hours. These are all necessary tasks that are directly related to the bus driver's role and the operation of the vehicle for their work purposes. Therefore, the correct answer to which of these counts as on duty hours for a bus driver would be c. All of them.