Read this paragraph from a story. Hector followed the man in the black trench coat down the alley. Hector ducked behind a trashcan as the man looked from side to side before knocking a pattern on a door. The door opened and the man spoke quickly in a language Hector did not understand. He handed a paper through the door. Just then, Hector heard someone running and the door slammed shut as a woman appeared at the entrance to the alley. “Stop!” she yelled at the man in the trench coat, but the man turned and leapt up the wall of the building, somehow scaling it easily, and vanishing onto the roof.

Which detail about the man’s actions supports the idea that he is a spy?
A. He walks down an alley.
B. He looks from side to side.
C. He knocks in a pattern and hands a paper through the door.
D. He climbs up a wall easily and escapes onto the building’s roof.