While on routine patrol, police officers observed a driver making an illegal U-turn. After stopping the driver's car, they saw him reach under the driver's seat. They ordered him out of the car and saw a cellophane package protruding from under the seat. The package contained a white powdery substance, which the officers suspected to be cocaine.

a. The officers placed the driver under arrest and put him in the rear of their patrol car.
b. They then proceeded to search the rest of the driver's car.
c. In the trunk they found an assault rifle that was later determined to be the weapon used in a liquor store robbery.
d. Charged with that robbery, the driver moved to suppress the assault rifle as evidence on the grounds that the police did not have a warrant to search the trunk.