You are the first to arrive on the scene of a motor-vehicle collision. Your scene size-up reveals a tanker truck on its side with an unresponsive driver in the cab. Multiple bystanders are around the cab waving for you to come over and help the driver. Your immediate action should be to:

A) order the bystanders away from the truck.
B) assess and extricate the patient.
C) determine what material the truck is carrying.
D) make certain the tanker is not leaking.

A