Given the task definition and input, reply with output. In this task, you are given an impractical statement. You are also given three reasons (associated with "A", "B", "C") explaining why this statement doesn't make sense. You must choose the most corresponding reason explaining why this statement doesn't make sense.

They have to say hello to each other because they are leaving
(A) Saying hello means being friendly
(B)People say hello when they meet each other
(C)Saying hello to strangers can make them happy
B