Under which of the following conditions is the operator of an automobile not required to bring the vehicle to a full stop and wait until authorized to proceed?

a. outside of a residential district, the operator meets a school bus displaying alternately flashing red lights stopped in a lane of traffic directly ahead
b. on a divided highway, the operator of a vehicle sees a stopped school bus displaying alternately flashing red lights on the opposite side of the roadway where pedestrians are not permitted to cross the roadway
c. on a controlled access highway, an operator approaches a school bus displaying alternately flashing red lights from the rear of the school bus on the same side of the roadway
d. none of the above