You are en route to an emergency call when you approach a slow-moving vehicle on a two-way road. You can see oncoming traffic in the other lane. The driver has his windows up and does not realize that you are behind him. You should:

Select one:
A. remain at a safe distance until it is safe to pass.
B. quickly pass the vehicle on the left side.
C. pass the driver on the right-hand shoulder.
D. use your public address system to alert the driver.