question: a detective walked up to a door.  before he went inside, he heard: "NO BOB! DONT!" the there was a large BANG! well, the detective ran inside the door, to find a plumber, an electrician, and a traveling salesman.  there was also a dead woman on the floor with a gun beside her.  the detective immediately arrested the traveling salesman.  how did he know it was the traveling salesman that killed the woman?
choices.label: A B C D E
choices.text: plumber and electrician were girls wall outlet fixture dominatrix servant nanny