Bill Left the Same Party as Margaret, but Decided to Sleep

Bill left the same party as Margaret, but decided to sleep it off in the local park. The weather got cooler so he turned his car on to keep warm. The police found him asleep in the back seat.

A) Bill argues in his trial that since he was in the back seat, it was impossible for him to be considered ___ the car. ​
B) operating
C) running
D) driving
E) owning