You are heading to work on a back road. You see a border-collie-sized dog dart into the road, chasing cars. At first you think it belongs to one of the several houses in the area, but you don't see anyone chasing it, and the dog is going after the cars in a way that almost seems like the dog's been dumped there and thinks that each passing car is its owner, coming back to get him. The dog is not particularly thin, but its fur is matted, like it hasn't been brushed in a while. You have never seen this particular dog on this particular stretch of road before.
B. Keep going.
Enquiring minds want to know.