With no explanation, chose the best option from "A" or "B". James took his border collie on long walks because she was very high-energy. James wants to wear his border collie out, so she's not hyper at home.

A: James keeps his border collie on her leash and walks her for a full hour.
B: James lets his border collie off her leash, so she can run around as he walks.
A.